eli5 why do people get carsick/seasick?
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Mostly it’s the disconnect between their eyes and inner ear. Your eyes say you’re moving (or not moving) one way and your sense of balance is saying you’re moving in a different way.
One of the things our bodies evolved to do is to recognize the signs of being poisoned and take steps to eliminate the poison from the body. One of those signs are “your senses are screwed up” and one of those responses is “get whatever you just ate out of your stomach NOW.”
Basically, some people’s bodies throw a false positive for being poisoned and they’re trying to remove anything they ingested which might be poisonous, which means nausea and barfing.
Your body has a defense mechanism in case your eat poison. The balance center in your ears is very sensitive and being damaged by poison will make you feel off balance as one of the first symptoms of something poisonous. Your eyes indicate that your feeling of movement from your ears isn’t true. This triggers the defense mechanism: you throw up, expelling any poison not digested yet, and hopefully minimizing the damage.
Fast forward a few million years. Humans invent the wheel and eventually other forms of travel…. and something strange happened: it *is* possible to be inside a structure (car, boat, airplane, wagon, etc) that is moving, but inside it looks like you’re not moving. This sets off the defense mechanism at the wrong time. We call this seasickness, getting carsick, etc.
Look out a window. Make your body see – with your eyes – that yes, you are moving and bouncing around and that feeling of motion is legit. It’ll calm you down. But some people just *can’t* read a book in a moving car or whatever.
Has anyone here tried the Coast Guard Cocktail against seasickness?
Your body uses 3 distinct systems for balance because bi-pedal locomotion and balance is quite difficult. The systems are vision, inner ear, and sensory nerves.
On a boat you see long stretches of horizon that are stable and unmoving, however your inner ear and sensory nerves report motion, especially as you feel yourself rise and fall with the waves. The feedback your brain is getting is incompatible with each other and one possible reaction is nausea. This is theorized to have been a selected evolutionary trait as certain toxins can create similar sensations and through vomiting your body could expel the toxins before more is absorbed.
A similar thing happens in reverse with VR or car sickness. You see movement and motion, but your inner ear and sensory nerves report nothing is moving, or at least not in the same way that your vision is reporting.
More information on the balance system can be found here [https://www.kansashealthsystem.com/news-room/blog/0001/01/the-balance-system](https://www.kansashealthsystem.com/news-room/blog/0001/01/the-balance-system)
There is an acupressure point behind your ear.
Put an index finger behind the earlobe, move your finger back and slightly up and gently press and hold until nausea subsides.
There are patches that go in the same spot.
Because your equilibrium is a balance between what your eyes are seeing, what your inner ear is experiencing, and whether those things match your body is doing. If these things don’t match eachother, it confuses your brain.
If you are in a car, visually, you are moving fast, but your body is still, so it doesn’t match what your brain thinks your body is doing and the gravity being experienced by your inner ear. It is worse when you look down, for instance, because now your eyes are no longer helping your brain understand.
On boats you your inner ear experiences an up and down change in g-force, but your body is not going up and down, so your brain is again confused, since you aren’t jumping up or falling down.
Good question we had guys step off the dock on to the ship got sick and stayed that way until they got off it in Japan & Korea. That ship stunk all the way.
Your ears have fluid inside them so if the fluid gets disrupted (spinning around etc) it’ll make you feel dizzy and gross because you use your ears for balance / motion
I get it just sitting still – watching someone else play a First Person Shooter. I have to sit halfway across the room to lose the sensation. So it must work both ways. I’m moving but not moving, or I’m not moving but I’m moving. :p
Your body knows it’s moving, but that doesn’t match what your eyes are telling you.
The only other time this would happen is if you ingested something poisonous and it’s messing with your brain.
QUICK, GET IT OUT
(Chunder sounds)
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