Motion sickness is a very unpleasant condition that is classically associated with traveling in vehicles. Motion sickness occurs typically in children but it can affect even the adults. The issue is individual as some people are resistant and on the contrary some are very prone to the motion sickness.
The cause lies in our vestibular system. It is a small paired organ located in the inner ear (i.e. near the auditory system). Vestibular apparatus consists of three semicircular canals filled with liquid and crystals. The movement of crystals in the fluid irritates the cells of the vestibular apparatus that send information to the brain via the nerve fibers. The vestibular apparatus informs us about the position of the head and our body in surrounding space. It is absolutely necessary for keeping the balance.
Excessive irritation of the vestibular system may cause the motion sickness. Its increased sensitivity may be genetically determined and it is also more frequently present in children. The excessive stimulation is typical for traveling in vehicles. How does this happen? Imagine a man sitting in the back seat on a bus traveling on a bumpy road. He is bored and so he watches the landscape out of the window. His vestibular system gets confusing information. It perceives the movement of the bus forward, then information about movement up and down (bumpy road) and erroneous information about movement to the side caused by watching the passing landscape.
The vestibular apparatus thinks that we move forward (in the direction of the bus), in the vertical direction and that our head moves to the side. This excessive stimulation of the vestibular apparatus leads to the feeling of sickness.
Prevention and treatment
Every person with tendency to the motion sickness should take some precautions before travelling. In a car or on a bus, it inadvisable to sit as forward as possible, avoid watching the side landscape and look in the forward direction. This decreases the stimulation of vestibular tract. Before the travel, people should avoid eating or drinking alcohol and it is suggested to chew a gum. Air conditioning or at least sufficient ventilation also helps as the cool refreshing air suppresses feelings of nausea.
The sensitivity of the vestibular may be influenced by some medications that are suitable in case of long journeys. They have often also a slight sedative effect.