Nausea and Vomiting/motion sickness


I`m wondering what is going wrong in people who are susceptible to motion sickness. Is it due to a fualt in their balance mechanism, or because the vomit centre of the brain is over sensitive, & also, why do most people become less prone to motion sickness as they get older?

I can answer part of that anyway.  Motion sickness is caused by sensitivity in the inner ear.  The vestibular system in the inner ear detects poisons.  When it is overstimulated, it diagnoses poisoning and tells the brain to start vomiting.  In motion sickness, the vestibular system is overstimulated by motion, and the body thinks it's being poisoned and causes vomiting.This was proved by giving dogs poison and causing them to vomit.  When the inner ears of the dogs were removed, none of them vomited from the same poison.  

There is nothing particularly wrong with people who get motion sickness; their inner ear is just more sensitive to detecting poisons.  As people get older, their vestibular system probably gets more finely tuned.

Nausea and Vomiting

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I will try to answer all questions about nausea, vomiting, and emetophobia. I know many ways of preventing vomiting (or bringing it on). I have not vomited in over 40 years.


For over 19 years, I have answered questions about nausea, vomiting, and emetophobia on the internet. I wrote the Emetophobia FAQ (Frequently Asked Questions About Emetophobia) and the Vomiting FAQ (Frequently Asked Questions About Vomiting). I wrote the first website about emetophobia and started the first mailing list about emetophobia. Both are still in existence. I am moderator of the largest emetophobia site.

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