- In space, 80 per cent of astronauts suffer from motion sickness.
- Motion sickness is all in your head. Literally: it lives in your inner ear.
- It is not a disease but a normal hypersensitivity to movements you didn't create.
- Stopping is the most effective remedy. But that's not always possible.
In space, 80 per cent of astronauts suffer from it. Dizziness, nausea, vomiting: space agencies like NASA and ESA know the phenomenon well.
What it is
Motion sickness is not really a disease: it is more a kind of normal hypersensitivity to certain movements. It can occur with any form of movement or transport that you don't create yourself: car, boat, train, plane or spacecraft.
The scientific name is kinetosis, in which we recognise the ancient Greek verb kinein, meaning to move. It is not new either. Hippocrates was already describing cases of seasick sailors in the fifth century BC. The medical term nausea clearly contains the word naus, Greek for ship.
The mechanics
Motion sickness lives between your ears, more precisely in your inner ears, where the vestibular system sits. We call it an organ, but it is actually a complex system of canals, fluid and tiny hairs that signal accelerations and changes of direction.
Your brain fires a false alarm when it receives contradictory information. Your body signals movement, your eyes say you are sitting still reading. That conflict is the problem.
Remedies
Stopping is the most effective remedy. But transport is part of daily life and lying on the ground with your eyes closed is not always possible.
Based on research by Prof. Dr. Floris Wuyts, University of Antwerp.