Talking about our nervous system in previous posts brought back a memory (not so glorious but quite funny):I was visiting my family in the French Alps and we went grocery shopping which is always a lot of fun for me. I enjoy looking at all the traditional products and the new ones that came up since my last visit.
While we are in line waiting to buy cheese and salami (OF COURSE, WHAT ELSE!!!), the woman who was slicing some kind of ham, slices some of her finger too. So now, there is like a mini revolution in the store: everything stops, the manager comes in a hurry and is ready to call the paramedics, there is blood all over the place and no cheese for me… Being the only one there who is used to handle cuts and dressings, I offer to help. Since the store has an aisle for gauze, disinfectant and so on, the situation is resolved pretty fast. I am really happy with the nice white bandage around the woman’s index finger! Although the cut was not deep, the bleeding had taken a while to stop. I instructed her to continue to apply pressure on the wound like I did, and to hold her hand upward, to make sure it does not start bleeding again. But she keeps on pressing bellow the cut and holding her hand downward, against my advice and of course, makes it flow again. I now think she did it deliberately so she could claim the equivalent of workman’s comp. Anyway, dealing with the wound was fine, but for some weird reasons, watching the red slowly soaking the white gauze does an impression on me (something like the Hitchcock’ movie ”Spellbound” in which the hero has an anxiety attack every time he sees a white surface with parallel lines on it…). I start feeling nauseous, having cold sweats, and close to fainting. So now, there is not one but two sick people!
Fortunately I knew what to do: lie down flat on my back (sitting down will not do the trick) and raise the legs straight up for a few minutes. If it happens to someone next to you, apply the same technique to them as quickly as you can. I know, it is not very pleasant to do, especially on a dirty floor, but this is much better than risking hurting yourself falling down. And it is much more efficient than slapping them in the face!
This kind of fainting, provoked by strong emotions (fear, stress…), sight of blood or needles, or excessive heat, is called vasovagal syncope. It is due to an over-activation of the vagal nerve as a response to emotional stress. Remember, (as seen in the post on deep breathing) in response to stress, the sympathetic nervous system is engaged and increases the heart rate, perspiration, etc. In people who are prone to this type of fainting (mainly children and young women), there is a parasympathetic overcompensation by stimulating the vagal nerve too much which causes a sudden drop in blood pressure and heart rate. It can even cause involuntary urination, especially in case of strong fear. As a result of the heart slowing down, there is hypotension and the blood flow to the brain decreases which can lead to black out. By elevating the legs, you allow the blood to reach the head and the upper part of the body.
Of course, there are other and more serious reasons for fainting that should be addressed by a physician. Here I am only talking about the occasional episode with no other consequences than feeling silly in the middle of a French supermarket, for example.