When does it happen? Motion sickness can be do to many factors: inner ear infection, family history/genetic, migraines. Identifying trigger factors help. See your md to be sure your inner ear looks ok. Natural remedies may help some people though randomized, controlled trials are still pending on their benefit.
Motion Sickness. Stopping motion sickness depends on finding the cause of the disorder. For example simple motion sickness can occur on a boat or automobile ride, but more complex problems can occur from conditions of the inner ear or the eyes or brain. Abnormal motion sickness should be evaluated by your physician to find the cause so that proper treatment can be instituted.