What is motion sickness?

This is the answer prepared for another forum.

(Q: Why do I get a vomiting sensation while travelling. Not while in train or flight or when I am driving?)

I can give you a rough idea; expand by reading further. There are 'sensors' in our body to sense 'orientation in space' and 'movement in relation to space'. 1. Vestibular system;situated in the inner ear, 2. Eyesight, 3. Skin and deeper sensations from the soles of feet (while standing), buttocks, back of thighs (while sitting). 4. Sensations from joints, muscles and tendons (the ends of the various muscles)




The sensations brought into the brain is 'computed' and 'reflex' corrections made (corrective movements to balance the body and prevent fall). This requires well-functioning Central Nervous System (includes cerebellum and its connections, healthy muscular system and concerned nerve supply.



In motion sickness, it is due to excessive or imbalanced stimulation of the concerned organs. (eg., the vestibular system senses movement not corroborated by corresponding stimulation of the other 'sensors')



The 'balance centres' in the brain are wired to the 'vomiting centre' as well, hence vomiting is one symptom.



In flights and train journeys, the 'stimulation' is not excessive, hence you are comfortable. (There are people who can't tolerate flights; the vestibular system senses movement - acceleration, deceleration, angular movement etc. and imagine the speed!, while the visual cue is zero, even if one looks out through the window)



When you drive, your neck and body will tilt and adjust so that your eyesight and other body sensations described above are balanced.



There are 'grandma's treatment for motion sickness; 1. Carry a lime and smell it frequently 2. Rub on your forearm (with the opposite fist) and smell to manage the vomiting sensation.



Any qualified doctor can prescribe you medicines to prevent motion sickness; there may be medications that you can buy over the counter in a medical shop.