Monday, 21 October 2013

More medical myths

A comment someone made a few days ago inspired me.  She said, "It's possible to drown in a teaspoon of water", and it inspired me to think she's an idiot for believing something so patently obviously wrong.  It also inspired me to write another post on medical myths.  I am shocked that so many of these exist, but even more shocked that people continue to believe and propagate them. 

Take a deep breath, folks. We'll be going deep here. 

Myth: Pulling a grey hair will cause two to grow back in its place. 
Reality: Ha!  Only one hair grows in each follicle, so how exactly would that work?  In fact, pulling hairs can damage the follicle so the hair doesn't grow back at all.  Which is better: one white hair or no hair, baldy?  Yeah, I thought so. 

Myth: A base tan will protect me from sunburn, so I'm going to the tanning salon before I go to the beach.  I'm so smart!
Reality: No you aren't so smart.  Tanning equals skin damage whether it's from the sun or a tanning booth, and it won't protect you from getting burnt.  It also increases your risk of skin cancer by almost 70%.  Want a tan?  Spray it on.  And tell the Oompa Loompas hi for me. 

Myth: Don't wake a sleepwalker. 
Corollary: Sleepwalkers walk like zombies with their arms in front of them. 
Reality: No and no.  It isn't dangerous to wake someone while they are sleepwalking.  The proper thing to do is try to guide them back to bed.  And they walk normally just like any other person, unless they are having a midnight craving for braaaaiiiinssss. 

Myth: Do not, under any circumstances, let people with a concussion fall asleep or else they will die.  
Reality: I see this all the time on TV and in movies, and it drives me a little bit crazier each time.  "Stay with me!  No no, don't fall asleep!"  People who are concussed will NOT die if they fall asleep.  Excessive sleepiness is actually quite normal after a concussion, and the proper thing to do is let them sleep.  

Myth: I'm staying up all night partying on Friday night because I can make up for it by sleeping more over the weekend!  Woohoo paaaarty!!
Reality: Actually, this one is true.  If you lose a few hours over the week, you can make up for it by sleeping more during the weekend.  But if you routinely sleep until 2PM, that just makes you a lazy bum so get your ass out of bed. 

Myth: Im so drunk but I need to drive, so I'll have some strong black coffee and I'll be good to go!
Reality: NOOOOOOOOO!  Especially if you live near me, stay the hell off the road if you've been drinking.  I don't care what you put in your stomach, it will NOT magically decrease your blood alcohol level any faster.  The alcohol in your blood needs to be metabolised.  Full stop.  The caffeine may help wake you up a bit, but it will not sober you up.  So put the keys down.  Now. 

Myth: Blood in veins is blue and blood in arteries is red.  It must be true because it says so on the Internet.
Reality: There may be truth in advertising, but the Internet has led countless people astray, and this time it's you.  Blood is red.  Deep red.  You know, like blood red.  Have you ever heard of blood blue? No, of course not.  And the show Blue Bloods does NOT count.  

That's it for part 2.  There are lots more out there, and I welcome any comments and/or emails with more myths for me to bust.  I think Jamie Hyneman and Adam Savage would approve. 

16 comments:

  1. Hey Doc, why is it that some veins (or arteries... I don't know...) are blue?

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    1. Because you are seeing the veins through the skin. The actual veins are white-ish. Arteries are white too, for that matter.

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    2. I am a little curious as to why seeing the veins through the skin would make them appear blue.

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    3. It has mostly to do with optics and the skin's structure, but the simple version (and also the only version I know) is that the skin changes the way light is reflected, and veins are generally exactly at the right depth to cause the skin to appear bluer than it normally does.

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  2. I can't exactly say I've heard of the one about concussions, I have heard that it can be bad, but that's about it (maybe in regards to never waking up? like a coma?) again i'm sure that's wrong also.

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  3. I thought falling asleep after experiencing head trauma could cause you to go in to coma. I know when my aunt fell off her scooter and hit her head her husband (A doctor of some sort not sure) did not want her to fall asleep.

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    1. If you hit your head hard enough to go into a coma, it will happen whether you consciously fall asleep or not.

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  4. Yes - the concussion thing I had heard was that letting them sleep meant they were more likely to slip into a coma. Of course that may be utter BS too but it was certainly coma rather than sudden death that was the supposed issue.

    Incidentally, to do this in true MythBusters style, you're going to have to design a massive machine to thwack people on the head and then watch whether those who fall asleep slip into a coma - are you sure your insurance covers that Doc?

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  5. So wait. Why CAN'T you drown from a teaspoon of water? I can't say I know the exact definition of drowning but I believe that it means dying from water/liquid that entered the lungs. A teaspoon of water definitely can enter the lungs. Okay, it might not be enough to kill you... But what about half a glass of water? Can you drown from that?

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    1. I think that your lungs will simply absorb a small amount of water. It may irritate them and that can be a serious issue but it won't stop them functioning right away. When I did a pool-side safety course years ago we were told that the idea of pumping water out of the lungs of someone who had nearly drowned was a myth (there's another for you Doc').

      To drown I think you need to be in more liquid than your body can easily absorb. If you are a fully functioning adult then you would also cough a lot of it up again even if it was somewhat more. For someone who is paralyzed or doped out, however, and can't lift their head then it would not need to be deep - just deep enough to cover the mouth and have enough volume that the amount they could absorb would not lower the level sufficiently for them to breathe air again.

      As I understand it (which may not be very well) it's not the water in the lungs as such that's the issue - it's the lack of air. A teaspoon full can't cut off your air supply and neither would a glass full but a bucket full would likely be enough.

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    2. PS there may be a difference between the pool water I was being instructed on (non-salty) and sea-water (salty) in this context.

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  6. I read that once you lose sleep, you can't make up for it later. It seemed to make sense, but now I'm not sure.
    I mean, I prefer making up my lost sleep if I can.

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  7. I had a concussion 3 weeks ago and my mom insisted she had to keep waking me up every half hour. I tried to tell her she was supposed to let me sleep, but she refused to believe me.

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    1. This comment has been removed by the author.

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  8. is it truth that you have to drink at least 2 liters of water a day?
    and this is my favorite, if you swallow gum, it will take 7 years to digest it....?

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    Replies
    1. I believe both those were answered in his previous myth-debunking post.

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