Why do some people throw up when they get dizzy?
I can’t answer your question, but just thought I’d share that I know first hand that being sick from being dizzy is the worst sick feeling I’ve ever had. When I took “Human Physiology” in college, we had a lab class that we had to take along with the lecture class. At some point, everyone in the lab was going to be a subject of an experiment. Of course the instructor took volunteers first, and then started drafting people alphabetically. One day when the lab started, the instructor started calling names from the roll and assigning times from 30 seconds all the way up to 30 minutes. I got 30 minutes. The time that each of us were given was how long we were to be spun around on a barstool. I don’t really remember much of what exactly we were studying, but I do remember (after I was done being spun) a girl getting up in my face and going on and on and on and on about how cool it was that I couldn’t keep my eyes still. All I could think was, “Yeah… yuk it up… Why don’t you come a little closer, bitch… <urp>” (I was in a foul mood at this point) I managed not to puke until after class was over. I had to be taken home, as I couldn’t make it there myself. I also managed not to puke in my friend’s car on the way home either (I was able to give fair warning so that she could stop). Lemme tell you… the next two days were FUN, FUN, FUN!!!. You know that feeling when you’ve had WAY too much to drink? Ya know… the one where you lay down on your bed to go to sleep, and the room spins like mad, so you put your foot on the floor to try to make it stop (because your friends told you that would work), but it doesn’t really help that much, and it just becomes a race as to whether you will have to get up to puke or you will fall asleep first? Yeah, that feeling… now take that, and multiply it by about 50. Then take away the sleepiness, and replace it with acute concentration on your dizziness. If I look in the mirror really closely, I can still see the American Standard indention on my forehead. Wow, that suck… er… I mean… I highly recommend intense dizziness for a really cool high the next time you’re bored. 
Throwing up because you are dizzy is pretty much like throwing up because you are seasick or you’ve been riding in the backseat of the car too long.
Your sense of balance (in your inner ear) is thrown out of whack by the sensation of being dizzy. This can affect all parts of your body like your eyes, your ears, your nose, and your central nervous system.
Your body is basically saying to you in this situation, “I don’t like this. I’m confused. Please stop. If you don’t stop, I’m going to throw up.”
Then you puke and if you are still dizzy, you’re in for a long night.
Actually, I got to thinking about it, and here’s my WAG.
Two cavemen (George, and Chuck) each eat a poisonous plant.
George starts feeling bad, and dies. George had reproduced only once. His kid ate the plant with him, and died also.
Chuck starts feeling dizzy, and pukes up the poisonous plant. Chuck lives, and has many children, many of whom eat the poisonous plant, yet live due to Chuck’s “get dizzy and puke after eating poisonous plant” gene.
Now that most of us are now descendants of Chuck, our bodies (thinking us not very bright for not having learned from previous generations) think we may have eaten the poisonous plant when we become dizzy from other means, and our body’s response is to puke, thinking it is purging the stomach of the offending foliage.
In short: I think it is a survival mechanism that can get activated when not really needed.
Continuing on the poisonous plant concept, I have recently started having a similar response to cigarettes. Occasionally, but not depending on any particular variable that I have noticed, when I smoke 1 cig I will shortly afterwards become dizzy, nauseous, and have a strong feeling of getting ready to faint. I’ve never actually fainted from this, but it gets to the point where I can only see specks of light (i.e. tunnel vision). I will occasionally throw up however, and immediately feel much better. What’s with THAT? I haven’t eaten the darn stuff!
/Kate
kate, what you are reporting is two separate side effects of nicotine. a lot of the nausea is caused by nicotine receptors in the gut getting activiated (why we have nicotine receptors there, I have no clue), and some of it is caused by restricted blood flow through the body. Since your stomach is getting less blood, it goes into energy conservation mode. sometimes this includes jettisoning the contents, as it were.
this second effect of nicotine, the causing a change in blood pressure, can cause dizziness and tunnel vision. Known as orthostatic hypotension, this same effect happens when you stand up too fast.
Steve-o, you are in the right building, but on the wrong floor. The barfing up of poisonous plant material is a response which is very much a survival mechanism, and probably strongly tied to other bodily actions which involve vomiting. However, it’s a bit ambitious to claim that poisoned plants are the source of all vomity behavior.
BobT is the man on the money.
I was not trying to make such a claim. Actually, the scenario I painted was not intended to be specific to plants. The poisonous plant was intended to represent anything injestible that could be harmful to your body (bad food, alcohol, poisonous plant, feces, bad water, etc…).
I interpreted the OP as asking “how is it useful for the body to vomit when dizzy”. Perhaps I interpreted incorrectly, but that was my take on it. BobT explained what happens to make you dizzy, and said that this could result in vomiting, but I didn’t see it as an explanation for “how is it useful for the body to vomit when dizzy”.
I don’t think vomiting is necessarily useful to the body. I don’t see why it has to have a use. It’s just a reaction to some very nasty stimuli.
I believe I said it’s one way for the body to tell you to stop doing whatever your’re doing to make you dizzy. I don’t necessarily think it’s something we evolved. I don’t see any advantage to it when it comes to survival or breeding.
“Hey, look, the guys who puke have bigger offspring! I want to mate with one of them!”
Vomiting does not have to have a use, but it DOES have a use. Without any doubt, vomiting can save your life. I think it is probably an evolved process. George and Chuck didn’t have a grocery store with a government inspected food supply from which to get their eats. Nor, did they have a reference library in which to look up their possible eats for the day to see if they were safe to eat. They had to eat whatever they could get their hands on. If they couldn’t find something they normally ate that they had some degree of certainty was OK to eat, they had to experiment. Eating strange plants can be dangerous. Eating animals you find that are already dead can be dangerous. It would most certainly be advantageous to a guy if his body had some mechanism of getting rid of dangerous eats. I don’t think puking made potential mates more attractive… I think it made them not dead.
“Hey, look, the guys who don’t puke are dead, and have no offspring! I want to mate with one of them!" 
However, most mammals (if not all) vomit. At least my cat does it. I assume that other furry quadrupeds can as well. Birds can regurgitate food to feed their young.
If it’s a survival mechanism, it’s one that’s been around for a LONG time. Australopithicenes were puking in Olduvai Gorge I’m sure.
rats do not vomit. they are physiologically unable. thank god too, or else our rat poisons wouldn’t be quite so efficacious.
if you force-feed them enough whipped cream and then put the rat in the fridge for a few minutes, it tastes just like a twinkie. I shit you not.
okay okay, I in fact shit you.
rats do not vomit. they are physiologically unable. thank god too, or else our rat poisons wouldn’t be quite so efficacious.
if you force-feed them enough whipped cream and then put the rat in the fridge for a few minutes, it tastes just like a twinkie. I shit you not.
okay okay, I in fact shit you.
rats do not vomit. they are physiologically unable. thank god too, or else our rat poisons wouldn’t be quite so efficacious.
if you force-feed them enough whipped cream and then put the rat in the fridge for a few minutes, it tastes just like a twinkie. I shit you not.
okay okay, I in fact shit you.
rats do not vomit. they are physiologically unable. thank god too, or else our rat poisons wouldn’t be quite so efficacious.
if you force-feed them enough whipped cream and then put the rat in the fridge for a few minutes, it tastes just like a twinkie. I shit you not.
okay okay, I in fact shit you.
damn either vB, the WWW, or my goddamn PC, but I kept getting error messages and the like. I even reloaded the pages after each try, and was not rewarded with a post. and now it’s posted four times!!!
damn this feeble brain!
We believe you!
jb, the rule of thumb is that if you hit “submit”, your post made it. Even if you hit stop, or close the window, or get an error message, it made it, and will show up eventually. If you’re really worried about it, copy your post into a text editor, save it, and check again in 24 hours. If it’s still not there, ok, THEN you post it again.
The “puking to get rid of bad food” was the explanation I’d always heard, too. Why shouldn’t it occur in other animals, as well? It’s a pretty basic mechanism.
I’m pretty sure that the thing about rats being unable to vomit is a UL, too, but I’m not sure.
There are a lot of poisons which humans can consume without vomiting. You can chow down on many types of mushrooms without vomiting, or at least not vomiting until it’s too late and your liver is shot.
According to Britannica, vomiting is controlled by two parts of the brain in the medulla oblongata. One is creatively called “the vomiting centre” and this is the part of the brain that responds to different types of stress or disease and tells your intestinal track, in a sense, “Hey, back it up and throw it out.”
The other part is called the chemoreceptor trigger zone, which is the part that responds to toxins or other nasty stuff. Once it is triggered, it sends a message to the vomiting centre and … out we go.
I had long lectures on dizziness from my otolaryngologist, due to a recent ear operation that pretty much destroyed my sense of balance. The postoperative side effects on the nerves controlling balance are so severe and cause such intense dizziness, they told me they use powerful drugs to keep the patients unconscious for 24 hours after surgery until the nerves settle down. I even warned the anaesthesiologist that I had nightmares about waking up on the table. And of course, when they were lifting me up off the table, I distinctly remember waking up. I experienced the most intense dizziness, it was as if the entire room was spinning at about 4 revolutions per second. I started vomiting, which was a Really Bad Thing as they were lifting me up with my head back, and I aspirated it. I started choking, I couldn’t breathe, and I remember passing out from lack of oxygen. It was awful, I had nightmares about it for months. I should have sued that doctor for malpractice, he definitely deserved it.
But anyway, my doctor said that there are three senses of balance; vestibular (the ear), touch, and sight. We use our feet to sense our position to the earth, we use our sight to keep track of the horizon, and our vestibular organs to give an innate sense of “level.” He said that humans can live without their vestibular organs because we have sight that is good enough to compensate. But he said that experiments on animals showed that if they lose their vestibular sense, the animal will just curl up into a ball and sit there until it starves to death.