I joked about fainting at the sight of blood my entire life, up until a few seconds before I myself fainted at the sight of blood. After all, the idea sounded like some ridiculously melodramatic movie trope, or something that only happened to weak, pale children who hid inside instead of biking or playing football.
We were doing blood typing in my high school's biology class, and after the teacher pricked me, I looked at the red pearl of blood and my vision just completely blacked out. I woke up only a few seconds later on the ground, with no idea what had just happened.
It wasn’t like I had never seen my own blood before; I was 16 at the time, and had my fair share of rollerblade falls and tripping over my own feet. I had seen way more blood than I saw in bio, so I had no idea why I had such a visceral reaction to it this time.
I thought that maybe it was a one-time occurrence, but then I sat in on a hysterectomy and had to leave only 10 minutes after the operation started because I started seeing black again. That led me to realize that I only pass out when I see that blood is being drawn intentionally, such as in a blood prick or in an operation, whereas falling and scraping a knee is accidental.
After some research, I learned that the fainting is caused by vasovagal syncope, or a drop in heart rate and blood pressure due to a stressful trigger.
So, fainting at the sight of blood is probably a way of slowing down blood flow to decrease blood loss. Or, it could be a survival mechanism similar to how goats faint and play dead when they’re near predators. In the case of blood typing, I was the “goat” and the biology teacher was the “predator,” and I involuntarily passed out in order to appear dead and prevent the biology teacher from pricking me again. (which technically did work — he didn’t prick me again, so yay for that!).
Something curious I came across during my Google escapades was that fainting at the sight of blood is also known as hemophobia, or blood-injection-injury phobia. (I also learned that a bunch of pictures of blood pop up, which seems like some cruel irony.)
But that struck me as odd. A phobia is defined as an irrational fear of something that you know is harmless. For me, blood kind of does the opposite. I’m not scared of blood. I don’t even try to avoid blood — it just happens that whenever I do see blood, my body flips out even though my brain doesn't really mind. Many other people who faint at the sight of blood feel the same way.
Of course, none of this really has any relevance to people who don’t faint at the sight of blood, unless maybe you take this as sort of a public service announcement: don’t hate on people who faint at the sight of blood!
