Motion sickness (also known as car, sea, train, or air sickness) involves a group of symptoms, particularly nausea, caused by movement during travel.
- While traveling, people feel nauseated and dizzy and may break into a cold sweat and start hyperventilating.
- Doctors base the diagnosis on symptoms and the situations in which they occur.
- Ways to help prevent motion sickness include keeping the gaze and head as still as possible, getting some fresh air, not reading, not smoking or drinking alcoholic beverages before traveling, and sometimes taking a drug by mouth or skin patch.
- Eating soda crackers or sipping ginger ale may help relieve the nausea, but once vomiting has started, a drug such as ondansetron or granisetron may be needed.
Motion sickness occurs when the parts of the inner ear that help control balance (including the semicircular canals) are stimulated too much, as can occur when motion is excessive. It can also occur when the brain receives contradictory information from its motion sensors—the eyes, the semicircular canals, and the muscle sensors (nerve endings in muscles and joints that provide information about body position). For example, motion sickness commonly occurs during boat travel, when the boat rolls and rocks while the person looks at something that does not move, such as a wall. In this case, the rolling and rocking do not match the lack of movement in the wall.
The brain can also receive contradictory information if a person sees something moving excessively despite the person being still. This type of contradictory information may be received when, for example, a person watches a movie taken with a camera that shakes or plays a video game. Motion sickness may also occur in a moving car or other vehicle or on playground or amusement park rides. Space travelers can also be affected.
Some people are more susceptible than others. Motion sickness is more common among women and children between 2 and 12 years of age, as well as in people susceptible to migraines, who have labyrinthitis (a disorder affecting the inner ear), or who are pregnant or use hormonal contraceptives. Fear, anxiety, and poor ventilation increase the likelihood of experiencing motion sickness. Genetic factors may also increase susceptibility to motion sickness.
Symptoms may begin relatively suddenly. Typical symptoms are nausea, vomiting, and a vague feeling of abdominal discomfort. Also, the face may become pale, and the person may break into a cold sweat. Dizziness, headache, and fatigue may develop, and the person may feel sleepy or be unable to concentrate. Other symptoms (often as a prelude to vomiting) may include increased saliva production, swallowing excessive air (aerophagia), and abnormally rapid, deep breathing (hyperventilation). Hyperventilation may cause faintness.
Nausea and vomiting make the person feel weak. Prolonged vomiting can lead to low blood pressure and dehydration. However, symptoms tend to gradually subside when the motion stops or the person leaves the vehicle. Also, people who are on long trips, as on a ship, usually adapt to the motion (helped by the stabilizers used in modern ships to minimize motion) and gradually recover.
- A doctor's evaluation
Motion sickness is diagnosed based on a description of the symptoms and the circumstances in which they occur.
Prevention and Treatment
- Nondrug prevention and treatment measures
- Preventive drugs (such as scopolamine and antihistamines)
- Anti-vomiting drugs (such as ondansetron or granisetron)
Measures to reduce the person's perception of motion include the following:
- Keeping the eyes fixed on a distant object (for example, watching the horizon while on a boat)
- Choosing a seat where motion is felt least (such as the front seat of a car, a seat over the wings in an airplane, or the forward/middle cabin or upper deck of a ship)
- Keeping the head and body as still as possible
- Sitting face forward and in a reclining position
- Not reading
Measures to reduce the person's susceptibility to motion sickness include the following:
- Getting fresh air by opening a window, opening an air vent, or going to a ship’s top deck
- Not drinking alcoholic beverages (because it can aggravate nausea)
- Eating small amounts of low-fat, bland, starchy foods and not eating strong-smelling or strong-tasting foods
- Avoiding food and drink on short airplane trips, especially on small airplanes
- Possibly, not smoking
Before traveling, people who are susceptible to motion sickness can ask their doctor to recommend an over-the-counter drug or prescribe a drug to help prevent the disorder. People should take these drugs before motion sickness starts because they tend to be less effective after symptoms begin. Drugs include scopolamine (as a patch or as tablets), cyclizine, dimenhydrinate, diphenhydramine, meclizine, and promethazine (sometimes combined with caffeine). All of these drugs can cause drowsiness. Because they may cause agitation in infants and very young children, these drugs should not be given to them except under a doctor’s supervision. People doing activities that require alertness or concentration (including driving) should not take these drugs. These drugs also should not be taken with alcohol, sleep aids, sedatives, or other drugs that also cause drowsiness and decrease alertness.
If motion sickness develops, limiting food and drink to bland foods (such as soda crackers) and carbonated beverages (such as ginger ale) may help keep symptoms from worsening. If vomiting develops, an anti-vomiting drug, such as ondansetron or granisetron, can be given, sometimes by injection or as a skin patch.
Adaptation can be a particularly useful strategy for treating motion sickness. The more often a person is exposed to the stimulus that causes motion sickness, the less likely the stimulus is to cause a response. However, the reaction is specific to the stimulus, so a person who becomes accustomed to the motion of a large ship may still experience motion sickness in a small boat.
Some people try alternative therapies, such as wearing wristbands that apply acupressure or electrical stimulation or taking ginger, to prevent or treat motion sickness. These therapies are unproven, but some people find them helpful.
Drugs Mentioned In This Article
|Generic Name||Select Brand Names|
|diphenhydramine||No US brand name|