Motion sickness is an unpleasant sensation commonly seen in some vulnerable individuals when they are subjected to unnatural motion.
All persons can develop motion sickness if given the right stimulus. For example, even hardy sea men are seen to develop sea sickness (a form of motion sickness) during a stormy season.
However, those at risk may develop the symptoms even with mild motion.
Motion sickness can be caused by travelling in cars, boats, ships, trains, aeroplanes, submarines, space ships, riding amusement rides that spin, swinging on park or play ground swings etc.
Those at a high risk include children, women and so forth. 1-6
Children between ages 2–12 years are at high risk of motion sickness. It is seen that infants and toddlers up to 2 years are relatively immune to developing motion sickness.
Symptoms can range from mild to severe and serious. Frequent vomiting can lead to dehydration and low blood pressure in children. This makes it important to seek prompt medical attention if the child is severely affected.
Women due to hormonal changes are more at risk of motion sickness. This includes pregnant women, women who are menstruating and those taking hormonal preparations (hormone replacement therapy or oral hormonal contraceptive pills etc.).
Research suggests that there is a common underlying vestibular mechanism of causation between motion sickness and vomiting and nausea during pregnancy. Those women who have experienced motion sickness are more likely to vomit during pregnancy than those who have never had motion sickness (63% compared to 37%).
It is suggested that when the nausea and vomiting is mediated by vestibular system the threshold is lowered during pregnancy. In addition high levels of estrogen in blood raise the sensitivity to certain smells and tastes in pregnancy. This causes a heightened risk of motion sickness.
Individuals who suffer from migraine are at a higher risk of developing motion sickness. Usually these people get an attack of migraine while they are experiencing motion sickness.
A study showed that 50% of migraine patients had a history of motion sickness compared with only 20% of tension headache sufferers.
Motion sickness is also strongly associated with migraine in children and among young adults (university students). It is speculated that migraine leads to contractions and dilatations of brain and head blood vessels. This gives rise to attacks of headaches.
Studies show that frequent blood vessel constrictions lead to ischemia or lack of blood supply to the vestibular apparatus and the labyrinth especially during an attack of migraine. This raises the susceptibility to motion sickness.
In addition, those with migraine have a lower triggering threshold for nausea and vomiting at the brain center called the “vomiting center” which makes migraine sufferers more at risk of motion sickness and its associated symptoms of nausea and vomiting.
Anxiety and stress regarding fears of developing motion sickness often gives rise to actual development of motion sickness.