Why do I faint?

Whenever I hear someone lecturing about the circulatory system I faint.
Interestingly enough though, I don’t faint at the sight of blood, and am quite comfortable at witnessing open wounds.
Also, I and am able to research the subject of the circulatory system, on my own, in great detail. It is whenever is verbally read to me in detail, I pass out.

As far as I can tell it is not related to any other source;
just the verbal lecture of the circulatory system.

What’s going on? and Can it be prevented?


How often has this happened? Does it happen any other time besides when you hear something about the circulatory system? If it does, I think you should see your doctor for an underlying cause.

Most people call it “falling asleep in class”.

You gotta see the doc on this one.

IANAD, but I believe that people with long-Q syndrome (don’t ask, it’s a very subtle problem with the electrical flow in the heart) are prone to fainting and ventricular fibrillation.

It could be (now this is a WAG) that thinking about your heart causes you stress which then triggers the bad juice flow.

Not to cause you worry, but you need to get an EKG. Again, IANAD, so please see a doctor.

Seeing a doctor is definitely a good idea.

I just wanted to add though, it’s happened that way to me too.
I’m a medical technologist and deal with lots of blood every day with no problem. I’ve seen surgeries and autopsies with no problem. But when I hear someone talking in detail about vascular stuff I get lightheaded. I was touring the local blood center once listening to a tech describe the donation process and I had to lie down or fall down. Most embarassing, particularly since blood banking is an area I work in frequently without that happening at all.
I know it’s pretty much a psychological problem with me and I’ve thought it might go back to some bad memories I have of blood draws when I was a kid.
I don’t know what to tell you to to avoid it though. It’s gotten a bit better for me over the years as I don’t actually fall over any more, just get really fuzzy. When I feel it start I try to either get out of the situation or just not listen and divert my stupid brain with other thoughts.

In a young, generally healthy person, fainting that occurs while at rest (i.e. NOT during vigorous exercise), is usually benign. The medical term for fainting is syncope, which is pronounced SIN-KO-PEE.

Fainting that occurs predictably with exposure to unsettling thoughts or uncomfortable sensations is almost always due to so-called vasovagal syncope. Synonyms for this benign and common disorder are: vasodepressor syncope, neurocardiogenic syncope, and neurally-mediated syncope. Here is a link. Do a search for some others.

More rarely, syncope in a young person can be due to serious, potentially life-threatening causes. Clues to the presence of such an underlying disorder include family history, syncope with exercise, and syncope associated with chest pain. Conversely, if a person senses that they’re about to faint, and has even a few seconds of premonition, it’s probably vasovagal.

An extensive investigation is seldom necessary for a young person with non-exercise associated syncope. The reputable American Heart Association states as much. So, if you see a doc, don’t be concerned if nothing more is suggested in terms of tests, etc. Indeed, I would consider that a good sign.

You may want to insist on a full work-up by a cardiologist, just to be on the safe side.

I fainted for years with no explanation of the phenomenon. It didn’t happen very often, maybe once every couple of months, but it was concerning me. Most doctors just shrugged it off, or said they couldn’t find any reason for it, so not to worry.

It wasn’t until my mother, another fainter, had a rather severe faint in which she didn’t quickly recover, saw a cardiologist who discovered a heart arrythmia in her. I went to the same doctor, and in me they discovered a mitral valve prolapse. Nothing to be concerned with, really-- just sometimes a valve gets stuck, causing the blood to pool back into my heart which makes me faint. I take a mild heart medication now, and it seems to be helping.

I’d suggest you get checked out as thouroughly as possible, just to be sure.

I wouldn’t sweat it, if I were you. Dr.J does the same thing about blood draws when he’s on the pointy side of the needle. He’s fine drawing blood, but having blood drawn… The phlebotomists just go on and put his butt in the floor before they even put a tourniquet on him, 'cause he’s gonna end up down there anyway. (Why, yes, they do give him a lot of shit about it, why do you ask?) As Karl says, it’s most likely just a bit of vasovagal syncope and completely benign.

If you had these spells regularly, or with no discernable pattern like what Lissa describes, I’d be more concerned. But if it’s just under very narrowly defined circumstances like hearing a lecture about the vascular system, it’s worth mentioning to your doctor next time you’re in, but probably not worth scheduling a special appointment over.

I was diagnosed with neurocardiogenic syncope after I passed out while driving my car. I awoke in the car, which had flipped over; I was held in place in the seat by the seatbelt. I now take Atenolol every day, and no more problems (yet!) :slight_smile:

See your doctor!

That’s what I take!