Is there any health risk in cellular phones?

Cellular phones are taking ever increasing part in our lives, and I keep hearing people saying they are harmful to our health. Are there any scientific researches so far proving or disproving those claims? I found couple of semi-scientific articles: Is there any link between cellphones and cancer? which says: The possible connection between cellphones and cancer is controversial. Many years' worth of studies on cellphones and cancer have yielded conflicting results ... In one study that followed more than 420,000 cellphone users over a 20-year period, researchers found no evidence of a link between cellphones and brain tumors ... Another recent study suggested a possible increased risk of glioma — a specific type of brain tumor — for the heaviest cellphone users, but no increase in brain tumor risk overall. Long-term Cell Phone Use Linked to Brain Tumor Risk which says: Long-term use of both mobile and cordless phones is associated with an increased risk for glioma, the most common type of brain tumor, the latest research on the subject concludes. The new study shows that the risk for glioma was tripled among those using a wireless phone for more than 25 years and that the risk was also greater for those who had started using mobile or cordless phones before age 20 years. Though the second appears to conclude direct health risk, I'm pretty sure it's not yet any hard proof otherwise we would have seen huge lawsuits being filed all over the place. If really harmful, what factors are in place e.g. cellular phone model, signal strength, etc?

cancer brain cellular-phone bioelectromagnetics health-outcomes

The IARC has concluded that cell phones are a "possible carcinogen" due to the amount of evidence going both directions. The gist of it is summarised on the website itself: Cell phones emit radiofrequency energy, a form of non-ionizing electromagnetic radiation, which can be absorbed by tissues closest to where the phone is held. The amount of radiofrequency energy a cell phone user is exposed to depends on the technology of the phone, the distance between the phone’s antenna and the user, the extent and type of use, and the user’s distance from cell phone towers. Studies thus far have...

Most dentists - for most procedures - aim for a painless experience. If there is reason to keep some pain sensation intact, the dentist will inform you, and ask at appropriate intervals if you can feel pain. The efficacy of lidocaine and other local anesthetics depends on how closely your nerve distribution comes to the norm (they will inject the environs of the "normal" anatomical position of the nerve), how much anesthetic is injected, whether there are local factors which alter the local tissue pH (e.g. presence of an abscess or infection), how quickly it is removed from the site,...

People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group. At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are no worse than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison. You're right that a placebo wouldn't be...

Products high in calcium and magnesium should not be taken at the same time as antibiotics of the tetracycline (tetracycline, doxicycline, etc.) class, and milk should also be avoided with the quinolone class. They have the ability to bind the antibiotic in the gut, decreasing absorption. There is no reason to avoid dairy products while taking other antibiotics (such as the penicillin class, the one you're taking. The clavulanic acid is to increase it's strength against certain bacteria.) If the antibiotic package insert (or the pharmacists's instruction sheet) states it should be taken on an empty stomach, take it with...


The following tooth cracks are noticeable when a torch is shining on them (without the torch, they aren't visible). Are they serious? How viable are the teeth, and might they need to be replaced with false teeth in the near future? There is no pain experienced, but they seem to look quite bad:

Drug molecules, even when stored safely inside a tablet\capsule, inside a closed container, upon a high shelf (hopefully), are still exposed to the environment, and are thus exposed to all of the chemical processes and reactions that go about all around us (to name just a few - oxidation, hydrolysis, isomerization, polymerization, and more). Depending on the type of drug molecule and its functional groups, the molecule may undergo all kinds of chemical processes that may change its structure and\or properties. Therefore, drugs (and foodstuffs, as mentioned in the comment above) degrade and decompose over time, and are thus given...

I believe that those lines are craze lines. "Craze lines are merely cracks in the enamel that do not extend into the dentin." They occur because of stress in your teeth, ie: grinding your teeth, biting your nails, and even routine use of your teeth. What you've said also matches up with craze lines in that you don't experience any pain. Those craze lines aren't nearly as bad as some other teeth. Craze lines rarely lead to tooth breakdown, so you almost definitely won't have to get them replaced. There are some studies that say that craze lines may be...

In the blister shown, the likelihood of rupture is decreased because of the thickness of the epidermis on the palm of the hand, so you can leave it alone until the underlying area re-epithelializes. You'll know this is happening because of the decreased pain and the slow reabsorption of the fluid. Eventually you will just peal it off what's left of the blister, finding clean new skin underneath. But this is a great starting point for an answer about the treatment of blisters in general: is it better to leave them alone, drain the fluid, or de-roof them (take the...

In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you personally to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from the spread of the virus (AKA herd immunity). This is especially important to those within the population who cannot access the shot or cannot receive it due to a preexisting medical condition....


It seems the question of vaccine harm has been around at least as long as vaccines 1 . Specifically, the claim that vaccines can cause or contribute to autism has been hotly debated in the last decade. Many claim that there is a dangerous (possibly hidden) link. What is the current state of medical research on this topic? Could there be a conspiracy in the pharmaceutical industry to cover up a link?

I believe that those lines are craze lines. "Craze lines are merely cracks in the enamel that do not extend into the dentin." They occur because of stress in your teeth, ie: grinding your teeth, biting your nails, and even routine use of your teeth. What you've said also matches up with craze lines in that you don't experience any pain. Those craze lines aren't nearly as bad as some other teeth. Craze lines rarely lead to tooth breakdown, so you almost definitely won't have to get them replaced. There are some studies that say that craze lines may be...

This has been a controversial dispute for a long time and it can involve a lot of personal opinion, but I will try to answer this as scientifically as possible. There hasn't been any viable evidence that vaccines do cause autism. Several different theories have been proposed on why vaccines could cause autism, such as the ingredient in some vaccines thimerosal being harmful, but these have all been disproved by many different experiments. Many reliable sources such as the CDC 1 says that there is no link between autism an vaccines. A 2011 report 2 from the Institute of Medicine...

Products high in calcium and magnesium should not be taken at the same time as antibiotics of the tetracycline (tetracycline, doxicycline, etc.) class, and milk should also be avoided with the quinolone class. They have the ability to bind the antibiotic in the gut, decreasing absorption. There is no reason to avoid dairy products while taking other antibiotics (such as the penicillin class, the one you're taking. The clavulanic acid is to increase it's strength against certain bacteria.) If the antibiotic package insert (or the pharmacists's instruction sheet) states it should be taken on an empty stomach, take it with...

Because leprosy and multiple myeloma are conditions for which other treatment options are limited. All treatments have side effects, some more debilitating than others. The trick with pharmacology is to balance the benefit of treatment with the hazards of the side effects. Take cancer chemotherapy. The drugs we use for cancer chemotherapy are horrible poisons. We literally use derivatives of chemical weapons to treat cancer. Why do we deliberately poison cancer patients with what amounts to a weapon of mass destruction? Because if we don't, the cancer will kill them. In pharmacology there's a concept of a therapeutic window ....


Are there any health benefits to male circumcision?

It's been argued by various medical organizations that male circumcision has various medical benefits, such as reducing the risk of catching HIV, or reducing the risk of urinary tract infections, for instance. Are there any respectable scientific studies to back these assertions up?

People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group. At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are no worse than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison. You're right that a placebo wouldn't be...

There is evidence that neonatal circumcision saying that the benefits of circumcision outweigh the risks. According to a study done on neonatal circumcision [1] , the lifetime benefits of being circumcised outweighed the risks 100 to 1. Some of the risks people may associate with circumcision are very unlikely. Excessive bleeding only happens 0.1% of the time, infections 0.02% of the time, and loss of penis 0.0001% of the time. The percentage of death is only 0.00001%. Overall, it shows that males who have been circumcised require half as much medical attention as males who have not been circumcised. Also,...

I'm guessing the "iron" test was actually a hemoglobin test (though I'm certainly no expert in blood donation screens...). I suspect your nurse is reporting a folk tale rather than any true difference. Unfortunately, medical professionals are not always an excellent source of scientific knowledge. I looked for papers that have actually compared measurements in the two hands. Here's one: Patel, A. J., Wesley, R., Leitman, S. F., & Bryant, B. J. (2013). Capillary versus venous haemoglobin determination in the assessment of healthy blood donors. Vox sanguinis, 104(4), 317–323. https://doi.org/10.1111/vox.12006 Capillary fingerstick samples were assayed by HemoCue in 150 donors....

The short version is that in 2016 the polio vaccine changed. A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus is usually harmless, it reproduces in the gut and spreads through a fecal-oral route. In ~99% of infections it only causes mild diarrhea. In the remaining 1% of cases, however, it gets into the bloodstream and from there enters nerves, causing paralysis and/or respiratory failure. There are two types of vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). IPV is a shot of killed virus particles...


Is it helpful to a dentist to report pain during a procedure?

Suppose that a dentist is doing a standard dental procedure, e.g. drilling out decay, on me, and I start feeling pain as he does it. Assuming that I can handle the pain silently, so I don't need to report it for my own sake, is it at all helpful to the dentist's work for me to report it? Is this feedback that the dentist can use to detect issues with the actual work as he goes along, or would the only purpose of reporting it be to try to get him to do something to mitigate it, for the sake of my immediate experience? (Note: I'm using "me" as a stand-in for a typical patient.)

The seasonal coronaviruses attach exclusively to cells with a ciliated epithelium. Coronaviruses invade the respiratory tract via the nose. After an incubation period of about 3 days, they cause the symptoms of a common cold, including nasal obstruction, sneezing, runny nose, and occasionally cough (Figs. 60-1 and 60-2). The disease resolves in a few days, during which virus is shed in nasal secretions. There is some evidence that the respiratory coronaviruses can cause disease of the lower airways but it is unlikely that this is due to direct invasion. Other manifestations of disease such as multiple sclerosis have been attributed...

This has been a controversial dispute for a long time and it can involve a lot of personal opinion, but I will try to answer this as scientifically as possible. There hasn't been any viable evidence that vaccines do cause autism. Several different theories have been proposed on why vaccines could cause autism, such as the ingredient in some vaccines thimerosal being harmful, but these have all been disproved by many different experiments. Many reliable sources such as the CDC 1 says that there is no link between autism an vaccines. A 2011 report 2 from the Institute of Medicine...

Assuming the person is not taking anticoagulants, it's actually quite difficult to bleed to death from dismemberment of small members (hands, feet, penis, ears, nose, etc). Even large members such as arms and legs are often survivable because the body is very good at protecting itself from blood loss. For example, transected arteries will spasm and clamp off blood flow, and loss of blood will cause the body to divert blood flow away from the extremities and to the vital organs, thereby slowing the bleeding and allowing it to clot. In fact, the whole shock process can be viewed as...


What is excess blood from blood donations used for, and do we ever run out?

I regularly donate blood, however, I am curious as to what happens to my blood after I donate. Obviously some of it will go to people in emergency medical situations, as I intend. However, I have never heard of situations where someone died because we didn't have blood to donate to them; which makes it sound as if we don't have a blood deficit. That in turn makes me wonder what the excess blood is used for. So I have two related questions. First, do we ever have a blood deficit, situations where someone who could have been saved in a hospital dies because there wasn't blood to treat them? Or specifically situations like that caused by a lack of donors, not some logistical issue getting it where it needs to be. I have had the red cross call me and tell me that they have a 'deficit' many times, but frankly I hear it so often it leaves me questioning their definition of deficit. How often do we really run out? Related, if we don't run a deficit then what happens to my excess blood? I assume that some blood is regularly thrown out, but they figure it's better to have extra and risk it expiring then to run out during an emergency. However, if we have a high enough surplus do they do something else with it? For instance is it used for medical research? If we had say 5% fewer donors would it be our medical research which suffered, but not patients in the hospital? I will continue donating blood regardless of the answer here. I'm simply curious as to the result. Well that and it informs this discussion: https://skeptics.stackexchange.com/questions/28118/is-the-red-cross-policy-of-refusing-donation-from-homosexual-men-justified-by-in

Most dentists - for most procedures - aim for a painless experience. If there is reason to keep some pain sensation intact, the dentist will inform you, and ask at appropriate intervals if you can feel pain. The efficacy of lidocaine and other local anesthetics depends on how closely your nerve distribution comes to the norm (they will inject the environs of the "normal" anatomical position of the nerve), how much anesthetic is injected, whether there are local factors which alter the local tissue pH (e.g. presence of an abscess or infection), how quickly it is removed from the site,...

Great question! I think it's answerable as an overview, but please know this is only the tip of the iceberg.* Summary : Yes, we have deficits of certain blood products in certain locations at certain times that affect patient care. However, a small percentage of blood product does expire unused (because it wasn't the right product [see background] in the right place at the right time). A little background Donated blood is not usually transfused into a patient as whole blood. Instead, it's broken down into several components which are transfused in different clinical scenarios. The issues of storage and...

There is evidence that neonatal circumcision saying that the benefits of circumcision outweigh the risks. According to a study done on neonatal circumcision [1] , the lifetime benefits of being circumcised outweighed the risks 100 to 1. Some of the risks people may associate with circumcision are very unlikely. Excessive bleeding only happens 0.1% of the time, infections 0.02% of the time, and loss of penis 0.0001% of the time. The percentage of death is only 0.00001%. Overall, it shows that males who have been circumcised require half as much medical attention as males who have not been circumcised. Also,...

The definition of mortality rate that you've given does not match any practical definition I'm familiar with.* When people talk about the mortality rate of a disease, what they usually mean is the case fatality rate or the death-to-case ratio , which is simply defined as N d / N i , where N d is the number of deaths attributed to the disease over a given time period and N i is the total number of new cases of the disease observed during the same time period. By this definition, the current case fatality rate of 2019-nCov according to...


Does COVID-19 have a case fatality rate of 41%? Is this formula correct?

According to the data on the Johns Hopkins Coronavirus Tracker , as of 3rd February 2020 there were 17491 confirmed cases of COVID-19 globally, 536 total recoveries and 362 deaths. From my non-expert calculation this implies a mortality rate of: (Nd / (Nd + Nr)) * 100 = 41% where: Nd is the total number of deaths, Nr is the total number of full recoveries. This leaves 16593 people still suffering from the disease who have neither recovered or died. This is in stark contrast to the publicly disseminated value of ~2% mortality, so have I made a mistake in my calculation or assumptions, or is COVID-19 much more dangerous than commonly claimed? [After a helpful discussion in the comments, 'mortality rate' is not the correct term to use here, instead I should say ' Case Fatality Ratio '.]

virus infectious-diseases death covid-19

This event occurred in the US. In the US, enzootic (dog-to-dog) canine rabies virus has been virtually eliminated through vaccination and stray control programs, making wild animals the primary concern. It is quite true, as @EMT_Jedi stated, that rabies is usually caused by an animal's saliva, usually introduced by a bite (e.g. rabid cats, raccoons, etc.) However, this is not true of bat-related rabies. There is reason to be vaccinated after any strange contact with a bat. The most dangerous and common route of rabies exposure is from the bite of a rabid mammal. An exposure to rabies also might...

Let's get a few things out of the way... Sex is normal ( 1 ). Sexual desire and arousal are normal ( 2 ). Asexuality is normal ( 3 ). Masturbation is normal ( 4 ),( 5 ). There is no problem whatsoever with these three things, although everyone blushes when they talk about them. Is Masturbation healthy? Downsides : Masturbation is not risk free. It is about as dangerous as chewing or walking ( 6 ). Some side effects are irritated skin and ruptured penis, but only if you really, really, really overdo it (Once or twice a day...

The definition of mortality rate that you've given does not match any practical definition I'm familiar with.* When people talk about the mortality rate of a disease, what they usually mean is the case fatality rate or the death-to-case ratio , which is simply defined as N d / N i , where N d is the number of deaths attributed to the disease over a given time period and N i is the total number of new cases of the disease observed during the same time period. By this definition, the current case fatality rate of 2019-nCov according to...

It is likely you are not hearing the ultrasound itself (typical frequencies are upwards of 1 MHz , far beyond what the human hearing system is capable of detecting). You are probably hearing coil whine from the electronics -- switched-mode power supplies in particular tend to operate towards the upper end of the hearing range, and the intensity of this sound changes as the power consumption does (eg. when the imaging system goes from "idle" to "active").


How can I prevent a cold from spreading to the people around me?

I have to attend classes at the university, band rehearsals, I live with my family, so I come close with many people during the day. I have to meet most of these people on a daily basis, even when I have the (common) cold. How can I prevent it from spreading to the people around me?

This has been a controversial dispute for a long time and it can involve a lot of personal opinion, but I will try to answer this as scientifically as possible. There hasn't been any viable evidence that vaccines do cause autism. Several different theories have been proposed on why vaccines could cause autism, such as the ingredient in some vaccines thimerosal being harmful, but these have all been disproved by many different experiments. Many reliable sources such as the CDC 1 says that there is no link between autism an vaccines. A 2011 report 2 from the Institute of Medicine...

There are lots of things you can do to be a responsible and considerate individual. Props for even asking this question! Cover your cough to prevent air-borne transmission with the inner part of your arm or your shoulder- whichever come into contact with other people less. Wash your hands with water and soap regularly for at least 20 seconds. That means before every meal and bathroom trip at least! Try as hot as you can bare so that it kills the bacteria. Carry hand sanitizer or some antibiotic wipes in case you don't have access to a sink or water....

Let's get a few things out of the way... Sex is normal ( 1 ). Sexual desire and arousal are normal ( 2 ). Asexuality is normal ( 3 ). Masturbation is normal ( 4 ),( 5 ). There is no problem whatsoever with these three things, although everyone blushes when they talk about them. Is Masturbation healthy? Downsides : Masturbation is not risk free. It is about as dangerous as chewing or walking ( 6 ). Some side effects are irritated skin and ruptured penis, but only if you really, really, really overdo it (Once or twice a day...

There is evidence that neonatal circumcision saying that the benefits of circumcision outweigh the risks. According to a study done on neonatal circumcision [1] , the lifetime benefits of being circumcised outweighed the risks 100 to 1. Some of the risks people may associate with circumcision are very unlikely. Excessive bleeding only happens 0.1% of the time, infections 0.02% of the time, and loss of penis 0.0001% of the time. The percentage of death is only 0.00001%. Overall, it shows that males who have been circumcised require half as much medical attention as males who have not been circumcised. Also,...


Why do doctors prescribe steroid tablets even though they know the side effects?

Sometimes doctors prescribe steroid tablets to suppress pain for diseases, such as arthritis . Why do they prescribe it even though they know the side effects?

I think a missing bit of information that might help you get a better sense of this practice is: steroids are miracle drugs. OK, that was in jest - no miracles here. Truth be told, though, if there is a single class of drugs that has added more quality-adjusted life-years to human history than any other, steroids must be competing with just a few antibiotic classes for that title. To make clear what we’re talking about, the term “steroid” as a label for drugs generally refers to glucocorticoids (GCs) - drugs that act like cortisol, an endogenous steroid hormone. Commonly...

Assuming the person is not taking anticoagulants, it's actually quite difficult to bleed to death from dismemberment of small members (hands, feet, penis, ears, nose, etc). Even large members such as arms and legs are often survivable because the body is very good at protecting itself from blood loss. For example, transected arteries will spasm and clamp off blood flow, and loss of blood will cause the body to divert blood flow away from the extremities and to the vital organs, thereby slowing the bleeding and allowing it to clot. In fact, the whole shock process can be viewed as...

People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group. At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are no worse than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison. You're right that a placebo wouldn't be...


Would the human seasonal coronaviruses be just as deadly as COVID-19 in a population with no prior immunity?

Presuming that we were able to find a person who was never exposed to any of the human seasonal coronaviruses (part of the viruses that cause the common cold), would the virus be just as deadly for that person as the SARS-CoV-2 currently circulating around the world? Or is SARS-CoV-2 uniquely dangerous?

It turns out the answer to this is fairly simple, and but not terribly easy to find. In the 1800s a Belgian named Adolphe Quetelet (1796–1874) performed some statistics on the weights and heights of people in Europe and Britain (chiefly France and Britain) and published his seminal work, Sur l'homme et le développement de ses facultés, ou Essai de physique sociale (Treatise on Man and the Development of his Faculties, or Essays on Social Physics) in 1835. The relevant section for this can be found as a PDF for free (I believe) at the Wiley Publishing journal Obesity Research...

The definition of mortality rate that you've given does not match any practical definition I'm familiar with.* When people talk about the mortality rate of a disease, what they usually mean is the case fatality rate or the death-to-case ratio , which is simply defined as N d / N i , where N d is the number of deaths attributed to the disease over a given time period and N i is the total number of new cases of the disease observed during the same time period. By this definition, the current case fatality rate of 2019-nCov according to...

The seasonal coronaviruses attach exclusively to cells with a ciliated epithelium. Coronaviruses invade the respiratory tract via the nose. After an incubation period of about 3 days, they cause the symptoms of a common cold, including nasal obstruction, sneezing, runny nose, and occasionally cough (Figs. 60-1 and 60-2). The disease resolves in a few days, during which virus is shed in nasal secretions. There is some evidence that the respiratory coronaviruses can cause disease of the lower airways but it is unlikely that this is due to direct invasion. Other manifestations of disease such as multiple sclerosis have been attributed...


Things like gender and age and height and weight make perfect sense to me, but I don't really see why most doctors ask for your race. Is there a medical reason behind this or is it just for identification purposes?

epidemiology research genetic-predisposition race ethnicity

In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you personally to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from the spread of the virus (AKA herd immunity). This is especially important to those within the population who cannot access the shot or cannot receive it due to a preexisting medical condition....

Race and ethnicity are risk factors in many diseases. Examples include, but are not limited to, cystic fibrosis and spinal muscular atrophy. There is also an epidemiological purpose of collecting this information. It is important to know if some disease is affecting some races or some ethnicities disproportionately. This is how it was found out that race or ethnicity is a risk factor in certain diseases in the first place. RFERENCES: Sheets L, Johnson J, Todd T, Perkins T, Gu C, Rau M. Unsupported labeling of race as a risk factor for certain diseases in a widely used medical textbook....


Why should I avoid milk when on antibiotics?

I'm taking antibiotics (specifically, amoxicillin clavulanate ) to fight off an ear infection. As she prescribed my antibiotics, my doctor told me not to eat milk products for a few days, then only eat yogurt until I was off the antibiotics altogether. To be honest, I'm thinking about ignoring this advice and just reducing the milk products I eat. On a typical day, I drink multiple glasses of milk, eat of bowl of oatmeal with milk, eat meals with lots of cheese, and eat ice cream at night. Cutting all of this out for a few days leaves me without much to eat! What are the downsides to eating milk products while on antibiotics? Is it just that, since my gut bacteria will be weakened, I risk digestional problems? Or can the consequences be more severe?

medications gastroenterology antibiotics milk gut-microbiota-flora

Overall, there has been inconsistent data on the effects of using zinc lozenges to treat the common cold. Most studies have also been done on children, which may lead to more uncertainty about its effects on adults, but some of the studies I will mention have been tested on adults. One study showed the effects of using zinc to prevent the common cold in schoolchildren. They found that between the two groups they studied (one took zinc sulfate tablets, the other placebos) that the zinc-supplemented group had less of a chance of getting the cold. They concluded that zinc supplements...

I believe that those lines are craze lines. "Craze lines are merely cracks in the enamel that do not extend into the dentin." They occur because of stress in your teeth, ie: grinding your teeth, biting your nails, and even routine use of your teeth. What you've said also matches up with craze lines in that you don't experience any pain. Those craze lines aren't nearly as bad as some other teeth. Craze lines rarely lead to tooth breakdown, so you almost definitely won't have to get them replaced. There are some studies that say that craze lines may be...


What should I consider when deciding to remove a blister or not?

While playing indoor soccer a couple days ago, I was fouled and fell forwards so that my hand skidded across the court a bit. It left the blister as you see in the image here: What should I consider when deciding to remove this blister? I could open and drain this blister, removing the excess skin afterwards, or leave it as is. I figure since it's in a place that is likely to be touched/disrupted I should remove it since it's likely to open anyways.

In the blister shown, the likelihood of rupture is decreased because of the thickness of the epidermis on the palm of the hand, so you can leave it alone until the underlying area re-epithelializes. You'll know this is happening because of the decreased pain and the slow reabsorption of the fluid. Eventually you will just peal it off what's left of the blister, finding clean new skin underneath. But this is a great starting point for an answer about the treatment of blisters in general: is it better to leave them alone, drain the fluid, or de-roof them (take the...

Because leprosy and multiple myeloma are conditions for which other treatment options are limited. All treatments have side effects, some more debilitating than others. The trick with pharmacology is to balance the benefit of treatment with the hazards of the side effects. Take cancer chemotherapy. The drugs we use for cancer chemotherapy are horrible poisons. We literally use derivatives of chemical weapons to treat cancer. Why do we deliberately poison cancer patients with what amounts to a weapon of mass destruction? Because if we don't, the cancer will kill them. In pharmacology there's a concept of a therapeutic window ....

Great question! I think it's answerable as an overview, but please know this is only the tip of the iceberg.* Summary : Yes, we have deficits of certain blood products in certain locations at certain times that affect patient care. However, a small percentage of blood product does expire unused (because it wasn't the right product [see background] in the right place at the right time). A little background Donated blood is not usually transfused into a patient as whole blood. Instead, it's broken down into several components which are transfused in different clinical scenarios. The issues of storage and...


When does the use of headphones become harmful?

Generally, it is known if you listen to music through headphones a lot of time, you damage your ears. But how long should I use the headphones? And how loud can they be so as not to affect my hearing?

Using headphones at a sufficiently high volume level may cause cause trauma to cochlear structure in the inner ear which gives rise to temporary or permanent hearing impairment or deafness . Sound pressure is measured in decibels and exposure to 75dB (even after long exposure) are usually safe. However, long or repeated to sounds at above 85dB can cause hearing loss. The louder the sound, the shorter the amount of time it takes for NIHL to happen. The risk is higher especially in loud places as volume often needs to compete with the background noise. For example, the average sound...

I think a missing bit of information that might help you get a better sense of this practice is: steroids are miracle drugs. OK, that was in jest - no miracles here. Truth be told, though, if there is a single class of drugs that has added more quality-adjusted life-years to human history than any other, steroids must be competing with just a few antibiotic classes for that title. To make clear what we’re talking about, the term “steroid” as a label for drugs generally refers to glucocorticoids (GCs) - drugs that act like cortisol, an endogenous steroid hormone. Commonly...


Why are iron levels different in the left and right hands?

Yesterday I donated blood. When the nurse performed a finger prick test of iron using my left hand, she indicated that the level was too low. However, she then asked to perform the test again on my right hand. Surprisingly, the iron level was adequate. She said that this is a well known phenomenon, specifically that the dominant hand often has higher iron levels. (For references, I am right handed.) How can this be? I would have thought that, given blood circulates throughout the entire body, it would be uniform everywhere.

Great question! I think it's answerable as an overview, but please know this is only the tip of the iceberg.* Summary : Yes, we have deficits of certain blood products in certain locations at certain times that affect patient care. However, a small percentage of blood product does expire unused (because it wasn't the right product [see background] in the right place at the right time). A little background Donated blood is not usually transfused into a patient as whole blood. Instead, it's broken down into several components which are transfused in different clinical scenarios. The issues of storage and...

In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you personally to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from the spread of the virus (AKA herd immunity). This is especially important to those within the population who cannot access the shot or cannot receive it due to a preexisting medical condition....

I believe that those lines are craze lines. "Craze lines are merely cracks in the enamel that do not extend into the dentin." They occur because of stress in your teeth, ie: grinding your teeth, biting your nails, and even routine use of your teeth. What you've said also matches up with craze lines in that you don't experience any pain. Those craze lines aren't nearly as bad as some other teeth. Craze lines rarely lead to tooth breakdown, so you almost definitely won't have to get them replaced. There are some studies that say that craze lines may be...


Do zinc lozenges really help the common cold?

For years I've been seeing advertisements for zinc supplements for the common cold, and I've heard recommendations from people who swear that they work, either wiping out a cold completely or shortening its duration. The studies I have seen were for zinc gluconate specifically. Apparently, once they had a nasal spray that was even more effective, but was pulled off the market for causing permanent anosmia. Is it a placebo effect, or is there actually evidence that zinc helps? If so, does it depend on the formulation (zinc gluconate, zinc acetate or zinc citrate?) Are there any risks?

The short version is that in 2016 the polio vaccine changed. A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus is usually harmless, it reproduces in the gut and spreads through a fecal-oral route. In ~99% of infections it only causes mild diarrhea. In the remaining 1% of cases, however, it gets into the bloodstream and from there enters nerves, causing paralysis and/or respiratory failure. There are two types of vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). IPV is a shot of killed virus particles...


Why is the rate of circulating vaccine-derived poliovirus disease booming?

The wikipedia entry on polio vaccines has the 1st graph below, showing that the rate of vaccine derived polio has increased massively over the last few years, with the rate of 1089 cases in 2020 compared to 56 - 71 per year from 2010 to 2014. The WEF page on the vaccine has the second graph below, show a fairly modest increase in the rate of immunisation coverage over this time. What is the reason for a roughly 20 fold increase in vaccine derived polio in such a short period of time, when vaccination rate has increased by only a fraction? (source: who.int )

The short version is that in 2016 the polio vaccine changed. A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus is usually harmless, it reproduces in the gut and spreads through a fecal-oral route. In ~99% of infections it only causes mild diarrhea. In the remaining 1% of cases, however, it gets into the bloodstream and from there enters nerves, causing paralysis and/or respiratory failure. There are two types of vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). IPV is a shot of killed virus particles...

This event occurred in the US. In the US, enzootic (dog-to-dog) canine rabies virus has been virtually eliminated through vaccination and stray control programs, making wild animals the primary concern. It is quite true, as @EMT_Jedi stated, that rabies is usually caused by an animal's saliva, usually introduced by a bite (e.g. rabid cats, raccoons, etc.) However, this is not true of bat-related rabies. There is reason to be vaccinated after any strange contact with a bat. The most dangerous and common route of rabies exposure is from the bite of a rabid mammal. An exposure to rabies also might...

Drug molecules, even when stored safely inside a tablet\capsule, inside a closed container, upon a high shelf (hopefully), are still exposed to the environment, and are thus exposed to all of the chemical processes and reactions that go about all around us (to name just a few - oxidation, hydrolysis, isomerization, polymerization, and more). Depending on the type of drug molecule and its functional groups, the molecule may undergo all kinds of chemical processes that may change its structure and\or properties. Therefore, drugs (and foodstuffs, as mentioned in the comment above) degrade and decompose over time, and are thus given...

The IARC has concluded that cell phones are a "possible carcinogen" due to the amount of evidence going both directions. The gist of it is summarised on the website itself: Cell phones emit radiofrequency energy, a form of non-ionizing electromagnetic radiation, which can be absorbed by tissues closest to where the phone is held. The amount of radiofrequency energy a cell phone user is exposed to depends on the technology of the phone, the distance between the phone’s antenna and the user, the extent and type of use, and the user’s distance from cell phone towers. Studies thus far have...


Is it advisable for a healthy male in his early 40s to take the influenza vaccine?

Influenza vaccines do not have satisfactory effective rates of preventing flu. Flu vaccination reduces the risk of flu illness by between 40% and 60% among the overall population during seasons when most circulating flu viruses are well-matched to the flu vaccine, according to the CDC . This is not considered highly effective for a vaccine. Furthermore, there is the risk of mercury that is harmful to the body, according to Natural News . Does it make sense for a healthy male in his early 40s to take the influenza vaccine, particularly when flu is an irritant but nowhere near deadly? Flu jabs come with mercury danger and does not sound effective. I am a lay man, so I may have miss out something important. Please correct me if I am wrong.

The short version is that in 2016 the polio vaccine changed. A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus is usually harmless, it reproduces in the gut and spreads through a fecal-oral route. In ~99% of infections it only causes mild diarrhea. In the remaining 1% of cases, however, it gets into the bloodstream and from there enters nerves, causing paralysis and/or respiratory failure. There are two types of vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). IPV is a shot of killed virus particles...


Can being cold or wet be a significant influence in getting the common cold?

As most people know, it's a common thing to say something like "better wear a sweater, otherwise I'll get the cold tomorrow." In my limited understanding, the common cold is caused by a virus. How does being cold affect this? Can being cold and/or wet be a significant influence in your chances of 'catching' the common cold?

TLDR: The pathogenesis of eczema is multifactorial, but broadly follows a process of genetic (or epigenetic, in the case of the early gut microbiome) dysregulation relating to barrier integrity proteins like filaggrin with corresponding changes in the skin microenvironment's ceramide content. Following these changes in protein structure and function and lipid quantity, the compromised barrier is predisposed to irritation and infection, which leads to an abnormal immunological response as Th2 cells work to resolve inflammatory processes in the skin (it's not clear how B cells participate in the pathogenesis of eczema at this time). Treatment options for mild-moderate eczema are...

This is a pretty old old-wives tale, taking many forms: don't go out into the cold while it's raining, or without a hat, with wet hair, without a warm coat or scarf, without boots, etc., "or you'll catch your death of cold." The old wive's tale was immortalized by Jane Austin in her book, Pride and Prejudice , when the heroine's sister Jane falls ill after getting a soaking in the rain. This has been studied extensively. A New York Times article describes one such uncomfortable-sounding study: In the 1950's, Chicago researchers repeated the experiment on a larger scale with...


How do I know if I'm flossing correctly?

I recently started flossing regularly. However, I'm not sure if I'm doing it right because sometimes my gums bleed. If I floss the right way, should it never bleed? Aside from bleeding, how can I know if flossing makes a positive effect? What should I notice in 2 weeks time? How about 4 weeks? 3 months? 1 year?

There is evidence that neonatal circumcision saying that the benefits of circumcision outweigh the risks. According to a study done on neonatal circumcision [1] , the lifetime benefits of being circumcised outweighed the risks 100 to 1. Some of the risks people may associate with circumcision are very unlikely. Excessive bleeding only happens 0.1% of the time, infections 0.02% of the time, and loss of penis 0.0001% of the time. The percentage of death is only 0.00001%. Overall, it shows that males who have been circumcised require half as much medical attention as males who have not been circumcised. Also,...

Dental flossing, essentially is done to maintain periodontal health , in hard to reach areas. Areas which are not used to any "friction" so, they will react in a rather singular manner in comparison to our exposed gums, per say. Thus, providing you presently have good oral health i.e. you don't have gingivitis which causes bleeding of the gums amidst brushing. Initially, flossing will cause inflammation and minor bleeding however, if the bleeding is rather severe it could indicate a periodontal disease and require medical intervention. Gums, if they are "virgins" to interdental flossing scene, will be tender , and...

Race and ethnicity are risk factors in many diseases. Examples include, but are not limited to, cystic fibrosis and spinal muscular atrophy. There is also an epidemiological purpose of collecting this information. It is important to know if some disease is affecting some races or some ethnicities disproportionately. This is how it was found out that race or ethnicity is a risk factor in certain diseases in the first place. RFERENCES: Sheets L, Johnson J, Todd T, Perkins T, Gu C, Rau M. Unsupported labeling of race as a risk factor for certain diseases in a widely used medical textbook....

Let's get a few things out of the way... Sex is normal ( 1 ). Sexual desire and arousal are normal ( 2 ). Asexuality is normal ( 3 ). Masturbation is normal ( 4 ),( 5 ). There is no problem whatsoever with these three things, although everyone blushes when they talk about them. Is Masturbation healthy? Downsides : Masturbation is not risk free. It is about as dangerous as chewing or walking ( 6 ). Some side effects are irritated skin and ruptured penis, but only if you really, really, really overdo it (Once or twice a day...


Father gets chickenpox, but doesn't infect his two children. How is this possible?

My brother in law got chickenpox, yet somehow he didn't infect my two nephews, even though they are living together. According to wikipedia, varicella has an infection rate of 90%: Varicella is highly communicable, with an infection rate of 90% in close contacts. https://en.wikipedia.org/wiki/Chickenpox He got varicella over a week ago and the children are completely healthy, even though they have not had the disease yet nor are they vaccinated against it. How is this possible? Is the infection rate actually lower, than 90%? Is an outcome like this usual or plausible? edit: they did end up getting sick after all.

infection vaccination virus infectious-diseases chickenpox

To add to @BryanKrause's answer re: rare events happen all the time, the children are not out of the woods yet. The mean incubation time for a primary VZV infection (the clinical syndrome known as chicken pox) is 14 days, but often lasts up to 21 days (see Murray Medical Microbiology, Ch. 53). The father is infectious while shedding virus, usually via the lungs. This correlates with the period of time a patient is febrile. I wouldn't say the father didn't infect his children until he has been afebrile for 21 days.

What your government is proposing is a lot less than what was actually done in China. There, and perhaps that is still the case, large numbers of asymptomatic infected people were housed together in halls with only social separation between them, and masks to prevent others from infecting others. Your government is proposing to house the asymptomatic infected in hotels, presumably in separate rooms. We know that people who are infected because they have virus identified using PCR swabs of their upper airways. CT scans can show pulmonary lesions present even without cough or fever. And even speaking can aerosolize...

tl;dr Current research seems to indicate that the brain is responding to anticipation or visual stimulus of needles being inserted, not that any of the theories supporting acupuncture are correct. Steven Novella reviewed the following article : Chae Y, Lee IS, Jung WM, Park K, Park HJ, Wallraven C. Psychophysical and neurophysiological responses to acupuncture stimulation to incorporated rubber hand. Neurosci Lett. 2015 Feb 11;591C:48-52. doi: 10.1016/j.neulet.2015.02.025. I'm going to quote from Novella's review because it's easier for a lay person to read/understand, and I don't have full access to the paper. As background, he states: There have been in...


Reading numerous news articles about COVID-19, I got confused as to what is its main transmission route. In particular, I am confused as to whether it is direct landing of respiratory droplets in mouths and noses, contaminated surfaces, aerosols (i.e., suspensions of the virus in the air rather than respiratory droplets quickly landing in mouths or noses or on surfaces), or something else. On the one hand, the website of the Centers for Disease Control and Prevention (CDC) says that contaminated surfaces are not thought to be the main transmission route: It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads. ( Link ) The same website appears to suggest that the main transmission route is direct landing of respiratory droplets in mouths and noses: The virus is thought to spread mainly from person-to-person. Between people who are in close contact with one another (within about 6 feet). Through respiratory droplets produced when an infected person coughs or sneezes. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. On the other hand, the World Health Organization (WHO), like many other agencies, puts the main emphasis on washing hands. Here is the WHO's first and foremost piece of advice on how to prevent getting infected with the virus: Regularly and thoroughly clean your hands with an alcohol-based hand rub or wash them with soap and water. Why? Washing your hands with soap and water or using alcohol-based hand rub kills viruses that may be on your hands. ( Link ) Social distancing is mentioned on that webpage only as a second piece of advice, and, furthermore, the webpage implies that it is safe to approach coughing people as close as 1 meter away: Maintain at least 1 metre (3 feet) distance between yourself and anyone who is coughing or sneezing. Furthermore, I found an article saying that the virus wasn't detected in the air of hospital rooms with COVID-19 patients, but was detected on surfaces: When researchers in Singapore tested the air in the rooms of three Covid-19 patients, they found no virus particles on cleaned surfaces or in the air even when they took samples on days the patients were symptomatic and presumably shedding virus into the air, they reported this month in the Journal of the American Medical Association. In the room of the third patient, who shed more virus, virus particles were present on ventilation fans and numerous surfaces — but all air samples were negative. ( Link ) But the same article also says that Chinese researchers found COVID-19 aerosols near patients' toilets. My question: Actually what is the main way COVID-19 spreads?

covid-19 infection virus epidemiology coronavirus

Ear tubes do many things to help ear infections. The most important things they do are draining the ear of fluid and ventilating the ear. Overall, this will help your child hear better. The tubes also stop fluid from building up behind the ear drum, which should help prevent the ear infections. Stuff to watch out for There is always the possibility of ear infections coming back after the 6-12 months that the tubes will be in. There is also a minor chance of hearing loss because of scarring of the ear drum. The tube can become blocked, stopping it...

Assuming the person is not taking anticoagulants, it's actually quite difficult to bleed to death from dismemberment of small members (hands, feet, penis, ears, nose, etc). Even large members such as arms and legs are often survivable because the body is very good at protecting itself from blood loss. For example, transected arteries will spasm and clamp off blood flow, and loss of blood will cause the body to divert blood flow away from the extremities and to the vital organs, thereby slowing the bleeding and allowing it to clot. In fact, the whole shock process can be viewed as...

The confusion exists because there are conflicting pronouncements from various authoritative sources but also conflicting pronouncements from the same authority. Covid-19 is a respiratory infection spread by droplets that can be aerosolized (nuclear droplets) in certain situations such as by flushing toilets or in certain medical procedures such as intubation. However, it reaches the air it contaminates surfaces and this allows for the infection to be caught through the eyes nose and mouth with the virus being transferred from the hand. The data from Singapore and Taiwan show that handwashing and social distancing are successful in preventing disease transmission. However,...


Is SM-102 a safe ingredient in the Moderna vaccine, despite these safety warnings?

I recently saw a post online which called into question the safety of the Moderna vaccine through an interesting argument. One of the ingredients in the Moderna COVID-19 vaccine is the ionizable amino lipid SM-102. [Source] Information about this chemical can be found on this website . As expected, the description of this chemical is the following: SM-102 is an ionizable amino lipid that has been used in combination with other lipids in the formation of lipid nanoparticles.1 Administration of luciferase mRNA in SM-102-containing lipid nanoparticles induces hepatic luciferase expression in mice. Formulations containing SM-102 have been used in the development of lipid nanoparticles for delivery of mRNA-based vaccines. However, as a standalone chemical it seems to have many safety warnings and hazards. This information is available on the accompanying safety data sheet for SM-102 . Here are some of the listed hazards: WARNING This product is not for human or veterinary use. H310 Fatal in contact with skin. H351 Suspected of causing cancer H372 Causes damage to the central nervous system, the kidneys, the liver and the respiratory system through prolonged or repeated exposure. Now, my presumption is that these hazards are supposed to be overly cautionary, and also only apply to the direct handling of the raw chemical. But many people do not see it this way, and thus are reasonably skeptical about the safety of the Moderna vaccine. So, I have a couple questions: Questions. Are all these hazards relevant to the chemical's pharmacological use as part of an mRNA vaccine? Why? How are these hazards determined in the first place? Are there examples of other chemicals with similar hazards/warnings, which are ingredients in common medical drugs? Opposite to the previous question, are there chemicals with little to no hazards/warnings, which nevertheless form key components to actually dangerous drugs?

The MSDS linked to is for a product sold as a solution of 10% SM-102 in 90% chloroform. It's listed as "SM-102" because that's the interesting/useful thing that the company is selling. It's common for chemicals to be sold packaged with solvents to make a solution. Sometimes that solvent is just water, but if the product is not water-soluble in sufficient concentrations then other solvents may be necessary. Alcohol solutions are quite common, but for more hydrophobic chemicals it may be necessary to use more "exotic" solvents. Because chloroform is quite a dangerous chemical for people to be exposed to...

In the blister shown, the likelihood of rupture is decreased because of the thickness of the epidermis on the palm of the hand, so you can leave it alone until the underlying area re-epithelializes. You'll know this is happening because of the decreased pain and the slow reabsorption of the fluid. Eventually you will just peal it off what's left of the blister, finding clean new skin underneath. But this is a great starting point for an answer about the treatment of blisters in general: is it better to leave them alone, drain the fluid, or de-roof them (take the...

Your question contains a lot of misconceptions. A cure is definitely possible A cure could be found, proved, and proved safe, more quickly than a vaccine People and firms that could be working on cures are choosing to work on vaccines None of these are correct. Most virus-caused diseases have no cure: colds, Zika, Dengue, and so on. A tiny handful have treatments that can ease the course of the disease: you've heard of Tamiflu and so on. And some can be actually cured with medication. So the first assumption, that a cure exists to be found, is not a...

To add to @BryanKrause's answer re: rare events happen all the time, the children are not out of the woods yet. The mean incubation time for a primary VZV infection (the clinical syndrome known as chicken pox) is 14 days, but often lasts up to 21 days (see Murray Medical Microbiology, Ch. 53). The father is infectious while shedding virus, usually via the lungs. This correlates with the period of time a patient is febrile. I wouldn't say the father didn't infect his children until he has been afebrile for 21 days.


Is there any proof that acupuncture is an effective pain remedy?

I have heard of acupuncture being used for pain management. Are there clear scientific proofs that indicate it is more effective than a placebo treatment for pain? If so what types of pain has it been shown to effective for?

pain treatment-options effectiveness placebo acupuncture


I've googled through internet, and all I found was "what expiration dates mean". I found nothing about the underlying mechanism of expiration. As drugs are chemicals, why do they expire? Are there chemical reactions that produce other chemicals?

Drug molecules, even when stored safely inside a tablet\capsule, inside a closed container, upon a high shelf (hopefully), are still exposed to the environment, and are thus exposed to all of the chemical processes and reactions that go about all around us (to name just a few - oxidation, hydrolysis, isomerization, polymerization, and more). Depending on the type of drug molecule and its functional groups, the molecule may undergo all kinds of chemical processes that may change its structure and\or properties. Therefore, drugs (and foodstuffs, as mentioned in the comment above) degrade and decompose over time, and are thus given...

In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you personally to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from the spread of the virus (AKA herd immunity). This is especially important to those within the population who cannot access the shot or cannot receive it due to a preexisting medical condition....

Your question contains a lot of misconceptions. A cure is definitely possible A cure could be found, proved, and proved safe, more quickly than a vaccine People and firms that could be working on cures are choosing to work on vaccines None of these are correct. Most virus-caused diseases have no cure: colds, Zika, Dengue, and so on. A tiny handful have treatments that can ease the course of the disease: you've heard of Tamiflu and so on. And some can be actually cured with medication. So the first assumption, that a cure exists to be found, is not a...


As of time of writing it's quite common to see headlines about so-and-so who have tested positive for Covid-19, e.g. Canadian PM Justin Trudeau's wife, Sophie, tests positive for coronavirus, officials say However, these articles don't usually say how reliable the testing is. I couldn't find any recent information on it via Google, either (there are some results, e.g. this , but they are old). How accurate are the tests? What are the odds that Sophie Trudeau's results are a false positive, or that Justin Trudeau's negative result is a false negative?

Short answer: Sophie Trudeau's positive test may still mean 3 : 1 odds of not having contracted Covid-19, but the odds could also be far more towards having Covid-19. Justin Trudeau's negative test almost certainly means he was negative when tested. Of course, should Sophie be positive, that may have changed by now. Update: I found a web page of the FDA listing tests that have this Emergency Use Approval . Each of them has manufacturer instuctions that list their test results towards the end. Some of the submitted test results use ≈100 negative samples in the clinical evaluation. But...

The only approved inhaled vaccine is the flu vaccine delivered intra-nasally. It uses a live attenuated virus. There are a whole list of people who should not receive it because it's a live virus, and it works better for children, but only is 40% effective for adults. The main issue is The intranasal LAIV, recommended for children above the age of 2 years, induces a broader immune response wherein protection is not antibody mediated and probably involves undefined multiple correlates of protection. and that's with a live virus. How well would a dead inhaled virus work? Well, we have some...

People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group. At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are no worse than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison. You're right that a placebo wouldn't be...


Do you bleed to death after your penis is cut off?

I wonder If a person without knowledge and tools cuts off somebody's penis and then doesn't call an ambulance immediately, is there a chance a person may not bleed to death within a short time? I would also like to know if you can still urinate, while the cutting is done without some tool you put into urethra? I haven't found much related to this topic.

Assuming the person is not taking anticoagulants, it's actually quite difficult to bleed to death from dismemberment of small members (hands, feet, penis, ears, nose, etc). Even large members such as arms and legs are often survivable because the body is very good at protecting itself from blood loss. For example, transected arteries will spasm and clamp off blood flow, and loss of blood will cause the body to divert blood flow away from the extremities and to the vital organs, thereby slowing the bleeding and allowing it to clot. In fact, the whole shock process can be viewed as...

I'm guessing the "iron" test was actually a hemoglobin test (though I'm certainly no expert in blood donation screens...). I suspect your nurse is reporting a folk tale rather than any true difference. Unfortunately, medical professionals are not always an excellent source of scientific knowledge. I looked for papers that have actually compared measurements in the two hands. Here's one: Patel, A. J., Wesley, R., Leitman, S. F., & Bryant, B. J. (2013). Capillary versus venous haemoglobin determination in the assessment of healthy blood donors. Vox sanguinis, 104(4), 317–323. https://doi.org/10.1111/vox.12006 Capillary fingerstick samples were assayed by HemoCue in 150 donors....


Why will there be vaccines first before a cure for COVID-19?

I found this link on the internet: 70 vaccines are getting ready for coronavirus: 3 very promising Why is it that there will be vaccines before a cure? Shouldn't it be the other way around? What is the reason for the vaccine first then the cure?

Your question contains a lot of misconceptions. A cure is definitely possible A cure could be found, proved, and proved safe, more quickly than a vaccine People and firms that could be working on cures are choosing to work on vaccines None of these are correct. Most virus-caused diseases have no cure: colds, Zika, Dengue, and so on. A tiny handful have treatments that can ease the course of the disease: you've heard of Tamiflu and so on. And some can be actually cured with medication. So the first assumption, that a cure exists to be found, is not a...

Overall, there has been inconsistent data on the effects of using zinc lozenges to treat the common cold. Most studies have also been done on children, which may lead to more uncertainty about its effects on adults, but some of the studies I will mention have been tested on adults. One study showed the effects of using zinc to prevent the common cold in schoolchildren. They found that between the two groups they studied (one took zinc sulfate tablets, the other placebos) that the zinc-supplemented group had less of a chance of getting the cold. They concluded that zinc supplements...

One of the primary purposes of corticosteroids is to suppress immune activity and inflammation: that's exactly why they are used in asthma. Of course the immune system has an actual job besides causing nuisance inflammation: fighting infection. For some infections, the harm to the infected person caused by the immune reaction itself is worse than that of the pathogen itself, so steroids can help prevent damage or ease symptoms while the immune system continues to mount a response, without being hyper active. For others, immune suppression may be detrimental. Corticosteroids mediate the immune response by suppressing a variety of cytokines...


Advantages of transition from non-vegetarian to vegetarian

Influenced by PETA, a lot of people have already changed to vegan status. I would like to know how well the transition may work? It can be either in a physical or mental way. Some have changed for religious views, some for humanitarian reasons. But I would like to know the health beneficial aspects.

This is a question that cannot be answered by a simple yes or no. As a vegetarian for health purposes (who was a vegan for 1 year) I say that the human isn't supposed to be vegetarian, but rather an opportunistic omnivore. The fact that we can eat meat doesn't mean we have to. Most of people that went from non-vegetarian to vegetarian (no meat, no fish) felt better the following weeks, however the reasons could be numerous and ambiguous: Maybe they were eating too much meat until they stopped ? Maybe the meat they were buying was bad quality...


Why is thalidomide a current drug on the market?

Given the thalidomide birth defect disaster of the 1960s, why was it later approved by the U.S. FDA for treatment of leprosy (1996) and of multiple myeloma (2006)? Presumably, the teratogenic issues and problems with permanent nerve damage didn't go away, as the liver can convert the "good" enantiomer to the "bad." Thalidomide affects even non-pregnant women, so why approve a drug with known severe complications?

It is not possible. The regulation of human body temperature (thermoregulation) is very subtle. Wikipedia article about thermoregulation contains a very nice graph about that mechanism. The labels are not described in the text in detail and the reference in the caption does not include this picture. Picture is a work by one JW Dietrich and I also searched PubMed for this guy, but he has no works on this topic. Another more pragmatic picture is here. Fever or increased body temperature is almost solely caused by to the production prostaglandin E2 (PGE2) . PGE2 acts on the hypothalamus or...


How are ratios for one person CPR arrived at?

I have not had a CPR (Cardiopulmonary resuscitation) class in 10 or more years, but I used to take them all the time ( like yearly ). For one person CPR the ratio of compression to breaths was always changing. In the US there were two major providers of approved CPR training, It was not unusual for both to have different ratios as "the correct value" at the same time, and the following year, one or both would be different. How are the ratios determined? What impact if any do minor changes in the ratio have?

Note: The following is excerpted from an article written in 2005. For lay (Non trained) people, there are more updated recommendations. The following is an example of the process, not the current recommendations. To be effective, CPR must restore adequate coronary and cerebral blood flow. Interruptions in chest compressions lower coronary perfusion pressure and decrease rates of survival from cardiac arrest. In the first minutes of VF SCA, ventilation does not appear to be as important as chest compressions, but it does appear to contribute to survival from prolonged and asphyxial arrest. Certainly the ventilation rate needed to maintain a...

People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group. At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are no worse than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison. You're right that a placebo wouldn't be...


We recently got some new kittens and my step son is allergic to them. He mostly suffers from a runny nose, but also had itchy eye last night after he Left a robe in the kitten room all day Put it on after getting home from school Kept scratching his eye after playing with the kittens etc. Anyway, so he's trying an antihistamine to see if this will combat the allergies. From sites like WebMD I've read that the cat allergy is an overreaction of his immune system. Is the antihistamine doing something regarding his immune's system reaction or is it doing something about the symptoms? How does it work? Will his immune system learn how to behave whilst taking antihistamines? Would the process of learning be better or worse for taking them?

A very brief review of an allergic response is in order so that the answer makes sense. Think of a linked chain of events here. An "allergen" is something a person is allergic to, e.g., cat dander or pollen. When someone is exposed to an allergen, they either become allergic or not. In a susceptible individual, something in the allergen (called an antigen, usually a protein of some kind) causes the person's immune system to produce an antibody (or Immunoglubin, in this case Immunoglobin E, or IgE) to the antigen, which then circulates throughout the entire system. The individual is...

Most dentists - for most procedures - aim for a painless experience. If there is reason to keep some pain sensation intact, the dentist will inform you, and ask at appropriate intervals if you can feel pain. The efficacy of lidocaine and other local anesthetics depends on how closely your nerve distribution comes to the norm (they will inject the environs of the "normal" anatomical position of the nerve), how much anesthetic is injected, whether there are local factors which alter the local tissue pH (e.g. presence of an abscess or infection), how quickly it is removed from the site,...


Are there any side effects to cracking knuckles?

I constantly crack (or pop) my knuckles. Are there any negative (or positive) side effects to it? I like to crack my knuckles, but I want to stop if it can have negative effects. What have scientific studies said about this subject?

A common medical myth is that cracking your knuckles causes arthritis, but is has been shown that cracking your knuckles, and popping your joints in general, will not raise your risk for developing arthritis. 1 It has also been shown to not cause degenerative joint disease in your hand joints in old age. 2 However, cracking your knuckles does have some risks. One study from 1990, 3 showed that, while cracking your knuckles does not increase your risk of arthritis, it does impair your hand function. It was shown to lower grip strength and cause hand inflammation in habitual knuckle...

I'm guessing the "iron" test was actually a hemoglobin test (though I'm certainly no expert in blood donation screens...). I suspect your nurse is reporting a folk tale rather than any true difference. Unfortunately, medical professionals are not always an excellent source of scientific knowledge. I looked for papers that have actually compared measurements in the two hands. Here's one: Patel, A. J., Wesley, R., Leitman, S. F., & Bryant, B. J. (2013). Capillary versus venous haemoglobin determination in the assessment of healthy blood donors. Vox sanguinis, 104(4), 317–323. https://doi.org/10.1111/vox.12006 Capillary fingerstick samples were assayed by HemoCue in 150 donors....

The MSDS linked to is for a product sold as a solution of 10% SM-102 in 90% chloroform. It's listed as "SM-102" because that's the interesting/useful thing that the company is selling. It's common for chemicals to be sold packaged with solvents to make a solution. Sometimes that solvent is just water, but if the product is not water-soluble in sufficient concentrations then other solvents may be necessary. Alcohol solutions are quite common, but for more hydrophobic chemicals it may be necessary to use more "exotic" solvents. Because chloroform is quite a dangerous chemical for people to be exposed to...


How many times a week is masturbating good for health?

I'm 18 years old. Every weekend I watch a pornographic film and when it finishes, I do a hand job. In addition, on weekdays, I masturbate. My question is: Is it good for your health or not?

Race and ethnicity are risk factors in many diseases. Examples include, but are not limited to, cystic fibrosis and spinal muscular atrophy. There is also an epidemiological purpose of collecting this information. It is important to know if some disease is affecting some races or some ethnicities disproportionately. This is how it was found out that race or ethnicity is a risk factor in certain diseases in the first place. RFERENCES: Sheets L, Johnson J, Todd T, Perkins T, Gu C, Rau M. Unsupported labeling of race as a risk factor for certain diseases in a widely used medical textbook....

I believe that those lines are craze lines. "Craze lines are merely cracks in the enamel that do not extend into the dentin." They occur because of stress in your teeth, ie: grinding your teeth, biting your nails, and even routine use of your teeth. What you've said also matches up with craze lines in that you don't experience any pain. Those craze lines aren't nearly as bad as some other teeth. Craze lines rarely lead to tooth breakdown, so you almost definitely won't have to get them replaced. There are some studies that say that craze lines may be...

In the blister shown, the likelihood of rupture is decreased because of the thickness of the epidermis on the palm of the hand, so you can leave it alone until the underlying area re-epithelializes. You'll know this is happening because of the decreased pain and the slow reabsorption of the fluid. Eventually you will just peal it off what's left of the blister, finding clean new skin underneath. But this is a great starting point for an answer about the treatment of blisters in general: is it better to leave them alone, drain the fluid, or de-roof them (take the...


Why do corticosteroids harm COVID-19 patients?

This Science Daily article states that steroids could do more harm than good in treating coronavirus (COVID-19), referring to this The Lancet article . Understanding the evidence for harm or benefit from corticosteroids in 2019-nCoV is of immediate clinical importance. It's unclear to me how exactly the use of corticosteroids (which is a common treatments for Asthma patients) can do harm other than the vague explanation of "steroids also impair the immune system's ability to fight viruses". How exactly does the use of steroids harm the body in case of fighting a virus such as SARS-CoV-2 (2019-nCoV) that causes COVID-19?

covid-19 asthma virus steroids corticosteroids

One of the primary purposes of corticosteroids is to suppress immune activity and inflammation: that's exactly why they are used in asthma. Of course the immune system has an actual job besides causing nuisance inflammation: fighting infection. For some infections, the harm to the infected person caused by the immune reaction itself is worse than that of the pathogen itself, so steroids can help prevent damage or ease symptoms while the immune system continues to mount a response, without being hyper active. For others, immune suppression may be detrimental. Corticosteroids mediate the immune response by suppressing a variety of cytokines...

Race and ethnicity are risk factors in many diseases. Examples include, but are not limited to, cystic fibrosis and spinal muscular atrophy. There is also an epidemiological purpose of collecting this information. It is important to know if some disease is affecting some races or some ethnicities disproportionately. This is how it was found out that race or ethnicity is a risk factor in certain diseases in the first place. RFERENCES: Sheets L, Johnson J, Todd T, Perkins T, Gu C, Rau M. Unsupported labeling of race as a risk factor for certain diseases in a widely used medical textbook....


Why does whooping cough last so long and can the duration of cough be reduced?

Whooping cough is a chronic cough resulting from an infection with the bacteria Bordetella Pertussis. The cough resulting from the infection may last several weeks, and as such whooping cough is sometimes called the 100 day cough. Why is it that the Bordetealla Pertussis infection produces a cough that lasts so long compared to other infections, and is there anything that can be done to reduce the cough's duration?

As you have noted, the "paroxysmal" stage of a clinical case of pertussis, which involves the rapid, exhausting coughing fits and the characteristic "whoop" at the end can often be extremely long. While it usually lasts 1-6 weeks, it can persist for up to 10 weeks , followed by a convalescent period. One reason for the long duration of the cough is that by the time one has reached that phase of disease, they are largely beyond the help of antibiotics, which will not shorten the clinical course of the disease in infected patients , but are intended to prevent...

Because leprosy and multiple myeloma are conditions for which other treatment options are limited. All treatments have side effects, some more debilitating than others. The trick with pharmacology is to balance the benefit of treatment with the hazards of the side effects. Take cancer chemotherapy. The drugs we use for cancer chemotherapy are horrible poisons. We literally use derivatives of chemical weapons to treat cancer. Why do we deliberately poison cancer patients with what amounts to a weapon of mass destruction? Because if we don't, the cancer will kill them. In pharmacology there's a concept of a therapeutic window ....


I have read (a long time ago, in an old book) that butter is good for burns. Is this true, and if so what is it that helps? Is salted or unsalted butter better? And how should it be applied, and kept there?

I think a missing bit of information that might help you get a better sense of this practice is: steroids are miracle drugs. OK, that was in jest - no miracles here. Truth be told, though, if there is a single class of drugs that has added more quality-adjusted life-years to human history than any other, steroids must be competing with just a few antibiotic classes for that title. To make clear what we’re talking about, the term “steroid” as a label for drugs generally refers to glucocorticoids (GCs) - drugs that act like cortisol, an endogenous steroid hormone. Commonly...

Short anwser : Never put butter, oil, etc , on a burn. This would worsen the burn. Putting butter, oil, or anything else would trap heat and make the burn deeper. It would also make further treatment harder and would make the risk of infection higher : Don’t apply burn ointments. Like butter (or mayonnaise), these ointments, usually oil-based, won’t relieve pain but instead will trap heat, slow down healing, and increase the risk of infection. What to do instead : Once it happens, a burn is actually "cooking inside", and this for a while after the exposure, so the...

Note: The following is excerpted from an article written in 2005. For lay (Non trained) people, there are more updated recommendations. The following is an example of the process, not the current recommendations. To be effective, CPR must restore adequate coronary and cerebral blood flow. Interruptions in chest compressions lower coronary perfusion pressure and decrease rates of survival from cardiac arrest. In the first minutes of VF SCA, ventilation does not appear to be as important as chest compressions, but it does appear to contribute to survival from prolonged and asphyxial arrest. Certainly the ventilation rate needed to maintain a...

This has been a controversial dispute for a long time and it can involve a lot of personal opinion, but I will try to answer this as scientifically as possible. There hasn't been any viable evidence that vaccines do cause autism. Several different theories have been proposed on why vaccines could cause autism, such as the ingredient in some vaccines thimerosal being harmful, but these have all been disproved by many different experiments. Many reliable sources such as the CDC 1 says that there is no link between autism an vaccines. A 2011 report 2 from the Institute of Medicine...


Risks of blood donation with autoimmune diseases

People with autoimmune diseases are generally either forbidden or discouraged from donating blood. Example: People who have autoimmune diseases (such as autoimmune thyroid disease, ankylosing spondylitis) are advised not to donate blood. This is because there is a small risk of causing immune system disturbance and symptomatic disease in patients who receive blood from donors with autoimmune diseases. source Is there any more information in the literature about the cases? I'm especially interested in the "causing symptomatic disease in patients who receive blood" part.

The short version is that in 2016 the polio vaccine changed. A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus is usually harmless, it reproduces in the gut and spreads through a fecal-oral route. In ~99% of infections it only causes mild diarrhea. In the remaining 1% of cases, however, it gets into the bloodstream and from there enters nerves, causing paralysis and/or respiratory failure. There are two types of vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). IPV is a shot of killed virus particles...

The World Health Organization published a report entitled Blood Donor Selection: Guidelines on Assessing Donor Suitability for Blood Donation . Based on a review of scientific studies and other literature, it contains detailed recommendations for establishing blood donation programs, including which donors to accept or reject. It mentions several autoimmune diseases. From the non-communicable section (page 49), we have 5.1.4 Thrombocytopenia Individuals with thrombocytopenia should not be accepted as blood donors because of the risk of bleeding at the venepuncture site and because chronic thrombocytopenia may be associated with serious underlying haematological or other systemic disease. A past history of...

Because leprosy and multiple myeloma are conditions for which other treatment options are limited. All treatments have side effects, some more debilitating than others. The trick with pharmacology is to balance the benefit of treatment with the hazards of the side effects. Take cancer chemotherapy. The drugs we use for cancer chemotherapy are horrible poisons. We literally use derivatives of chemical weapons to treat cancer. Why do we deliberately poison cancer patients with what amounts to a weapon of mass destruction? Because if we don't, the cancer will kill them. In pharmacology there's a concept of a therapeutic window ....


Why is BMI related to the square of height?

I'm aware that the U.S. CDC defines BMI (Body Mass Index) as mass (in kg) divided by height squared (in meters squared.) The CDC then defines what ranges are considered underweight, healthy, or overweight broadly based on BMI (with different ranges by gender.) My question is: Why the square ? As any mechanical or civil engineer (or just anyone who is vaguely familiar with those topics) will know, if you scale something up proportionally, mass will scale with the cube of the increase in a particular dimension, not the square. Because, for a given material, mass is proportional to volume. Furthermore, since material strength usually scales with the cross-sectional area (not volume,) which is proportional only to the square of a particular dimension, making something larger usually requires scaling up supporting structures more than proportionally in order to maintain the same safety margins. (See: Square-Cube Law ) So, why are these principals not applied when dealing with human anatomy? Is there some reason why it isn't believed that humans should scale proportionally (or even super-proportionally in order to maintain similar load-bearing characteristics?)

I think a missing bit of information that might help you get a better sense of this practice is: steroids are miracle drugs. OK, that was in jest - no miracles here. Truth be told, though, if there is a single class of drugs that has added more quality-adjusted life-years to human history than any other, steroids must be competing with just a few antibiotic classes for that title. To make clear what we’re talking about, the term “steroid” as a label for drugs generally refers to glucocorticoids (GCs) - drugs that act like cortisol, an endogenous steroid hormone. Commonly...

Assuming the person is not taking anticoagulants, it's actually quite difficult to bleed to death from dismemberment of small members (hands, feet, penis, ears, nose, etc). Even large members such as arms and legs are often survivable because the body is very good at protecting itself from blood loss. For example, transected arteries will spasm and clamp off blood flow, and loss of blood will cause the body to divert blood flow away from the extremities and to the vital organs, thereby slowing the bleeding and allowing it to clot. In fact, the whole shock process can be viewed as...

It turns out the answer to this is fairly simple, and but not terribly easy to find. In the 1800s a Belgian named Adolphe Quetelet (1796–1874) performed some statistics on the weights and heights of people in Europe and Britain (chiefly France and Britain) and published his seminal work, Sur l'homme et le développement de ses facultés, ou Essai de physique sociale (Treatise on Man and the Development of his Faculties, or Essays on Social Physics) in 1835. The relevant section for this can be found as a PDF for free (I believe) at the Wiley Publishing journal Obesity Research...


My young son keeps getting ear infections. The otolaryngologist want to perform surgery to put tubes in his ear drums. How does putting a tube in the ear drum help with the ear infections?

Ear tubes do many things to help ear infections. The most important things they do are draining the ear of fluid and ventilating the ear. Overall, this will help your child hear better. The tubes also stop fluid from building up behind the ear drum, which should help prevent the ear infections. Stuff to watch out for There is always the possibility of ear infections coming back after the 6-12 months that the tubes will be in. There is also a minor chance of hearing loss because of scarring of the ear drum. The tube can become blocked, stopping it...

I'm guessing the "iron" test was actually a hemoglobin test (though I'm certainly no expert in blood donation screens...). I suspect your nurse is reporting a folk tale rather than any true difference. Unfortunately, medical professionals are not always an excellent source of scientific knowledge. I looked for papers that have actually compared measurements in the two hands. Here's one: Patel, A. J., Wesley, R., Leitman, S. F., & Bryant, B. J. (2013). Capillary versus venous haemoglobin determination in the assessment of healthy blood donors. Vox sanguinis, 104(4), 317–323. https://doi.org/10.1111/vox.12006 Capillary fingerstick samples were assayed by HemoCue in 150 donors....

I think a missing bit of information that might help you get a better sense of this practice is: steroids are miracle drugs. OK, that was in jest - no miracles here. Truth be told, though, if there is a single class of drugs that has added more quality-adjusted life-years to human history than any other, steroids must be competing with just a few antibiotic classes for that title. To make clear what we’re talking about, the term “steroid” as a label for drugs generally refers to glucocorticoids (GCs) - drugs that act like cortisol, an endogenous steroid hormone. Commonly...


Does the usage of sunscreen cause skin cancer?

I have heard that usage of sunscreen products causes skin cancer. Is this true, and if so, what are the ingredients in it that are reason for such a medical condition. Are there any safe products or methods of application that they don't harm skin.

People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group. At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are no worse than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison. You're right that a placebo wouldn't be...

The potential health risks of sunscreen include: The absence of UVA filters combined with a longer exposure time of the sunscreen user 1995 , 2005 , 2007 , 2007 . Suppression of the skin's production of melanin, a natural broad-spectrum photoprotectant 1995 , 2004 . Skin penetration (free radical generation) by sunscreen chemicals 1996 , 1997 , 2006 , 2007 . Cytotoxic and carcinogenic effects of nanoparticles (zinc oxide (ZnO) and titanium dioxide (TiO2) toxicity) 1999 . However TGA study from 2006 ( PDF ) concluded: There is evidence from isolated cell experiments that zinc oxide and titanium dioxide can...

In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you personally to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from the spread of the virus (AKA herd immunity). This is especially important to those within the population who cannot access the shot or cannot receive it due to a preexisting medical condition....


What forms of prevention of STIs are there?

Other than the condom, are there any other methods of preventing contracting STIs? If so, do any of these also provide an effective form of contraception?

Most dentists - for most procedures - aim for a painless experience. If there is reason to keep some pain sensation intact, the dentist will inform you, and ask at appropriate intervals if you can feel pain. The efficacy of lidocaine and other local anesthetics depends on how closely your nerve distribution comes to the norm (they will inject the environs of the "normal" anatomical position of the nerve), how much anesthetic is injected, whether there are local factors which alter the local tissue pH (e.g. presence of an abscess or infection), how quickly it is removed from the site,...

The CDC lists two: complete abstinence, and being in a long-term mutually monogamous relationship with an uninfected partner . Sexual intercourse naturally introduces microtears (small tears in the the epithelial layer) through which diseases can transfer between partners. One might think that additional lubrication would help with this, but the jury is most definitely out on that. I think it's pretty safe to say that if there was another clinically verified way of preventing STDs, the CDC would have put it on this list . (For example, they note that there are specific things you can be vaccinated against, namely...

Products high in calcium and magnesium should not be taken at the same time as antibiotics of the tetracycline (tetracycline, doxicycline, etc.) class, and milk should also be avoided with the quinolone class. They have the ability to bind the antibiotic in the gut, decreasing absorption. There is no reason to avoid dairy products while taking other antibiotics (such as the penicillin class, the one you're taking. The clavulanic acid is to increase it's strength against certain bacteria.) If the antibiotic package insert (or the pharmacists's instruction sheet) states it should be taken on an empty stomach, take it with...


Vitamin B12 is stored over a very long time such that vegans, for example, only get any signs or symptoms of B12 deficiency after a span of years, even though they have hardly any sources of the vitamin in their diets. The dose required daily to prevent disease seems to vary dramatically, or maybe it is very hard to determine accurately. For example: This site says pregnant women need less than 3 micrograms (µg)/day (where pregnant women need more than non-pregnant women). A friend of mine got her blood values in order by ingesting 7 µg/day. My apothecary person told me 500-1000 µg per day are needed to even start absorbing meaningful quantities by ingestion. My doctor prescribed 200 µg/day for me. Another factor is that apparently your intestinal bacteria determine the rate of absorption. So what is the amount of B12 needed per day? Please note that this is not about deficient absorption, where the amount would be above what healthy people need.

obstetrics b-12-supplements absorption-absorb apothecary prenatal-vitamins

The estimated daily requirement needed to maintain body stores of B12 varies, an estimate being from 2µg to 5µg, more if stores have been depleted in any way. It is estimated that the average person stores about 1 mg (1000 µg) of B12 in their liver, and other smaller amounts elsewhere. The recommended daily allowance assumes a 50% absorption rate of ingested B12. This is a good question to discuss the limits of medical science. How is the requirement for B12 determined? Longitudinal studies are those that follow people over many years (even decades.) Humans are not subjected to longitudinal...


Do adult braces have a medical need beyond cosmetics?

While middle/upper-class American parents often have their children get braces as teenagers, an adult getting braces out of his/her own volition could be viewed as a sign of vanity, much like plastic surgery. While in most communities, braces are seen as more socially acceptable than plastic surgery, both involve modifying the body to improve outward appearance to gain the attraction and respect of others. Do adult braces have a medical needs, are are they purely to alter cosmetic appearance?

dentistry cosmetics dental-braces teeth-alignment

There are certain types of malocclusion that are have been shown to adversely affect quality of oral health and quality of life, but these are far, far fewer than the number of people sporting braces, adult or adolescent. The need for braces in the average teen, therefore, is no greater than the average adult. If you think of braces for teens as a necessity, it is no less a necessity for adults, that is, appearance is probably the only significant result for both average teens and adults. However, increased longevity has led to the need to keep healthy teeth for...