For a lot of people out there, the sight of blood is no biggie. Then there are those of you that drop like a rock when you see a paper cut (you know who you are). But why does this happen? Is it all in your mind, or is there a physical reason why you pass out over a little blood?
It’s not all in your head. Well, it is, but it has to do with your actual brain: your vagus nerve, to be exact. For some people, blood triggers a vasovagal syncope. It sounds a lot crazier than it is: Your heart rate slows, your blood pressure drops, blood pools in your legs and the decreased blood flow to your brain makes you faint. Though this could be a sign of a more serious condition, for the most part, it is harmless and normal -- assuming you don’t injure yourself on the way down.
Sometimes, it’s not seeing blood that triggers people. It could be feeling overheated, hearing about something gory, reading about blood (I apologize if this article makes you feel woozy), standing for too long, a fear of needles or even a difficult poop (ouch). Your body, in response to a trauma or perceived threat, tries to help you relax, but overshoots and instead, you drop. It’s rare, only happening to 5 percent of people...but that’s 16 million people in the U.S., which is still a lot of people.
Researchers know it has to do with a misfire in the fight-or-flight response, but they’re not totally sure why it happens. Some think this may be a genetic trait dating back to cavemen. If one caveman attacked another, the second one could faint to slow the loss of blood and therefore try to survive. Plus, looking dead may have made the first cave dude back off. But, it could also just be a physical defect in the tone of your vagus nerve. Either way, it’s likely not because you are weaker -- you were born this way.
If you are among the 5 percent and feel a fainting spell coming on, first, sit down so you’re safer. If you can, clench your muscles to pull blood out of your legs and send it upwards through the body, so that it’s not pooling in one area. And remind yourself you are the boss. A study found that when people have a perceived aspect of control in a situation, they were less likely to faint.
And the good news is, once you know your triggers and know how to prevent it, you can eventually learn how to stop fainting. You can also keep yourself away from triggers like horror movies, but you might need to work a little harder if you're in the medical field. It's not a good look when your doctor or nurse is always fainting on you!