Motion sickness, historically associated with sailors reacting to the pitch and roll of ships, now affects people in cars, trains, planes and even in space, according to the New York Times. Symptoms can begin within minutes of movement starting and last for hours after it stops, typically beginning with a feeling of warmth, sweating and dizziness, sometimes progressing to headache, fatigue, nausea and vomiting.
While usually temporary, the condition can be disruptive enough to reshape people's lives. James Phillips, a vestibular neurophysiologist at the University of Washington, told the New York Times he had once planned to become a marine biologist, until seasickness during a research expedition changed his mind. "I just couldn't tolerate it, so I abandoned that career ambition," he said.
Why it happens
Scientists do not know exactly what causes motion sickness. One theory holds that it results from conflicting signals between the senses, such as when the eyes register a stationary page while the inner ear's motion-sensing systems detect movement, according to Paul DiZio, a cognitive neuroscientist at Brandeis University. A newer and increasingly popular theory, DiZio told the newspaper, is that the brain builds an internal prediction of how motion should feel, and sickness follows when actual sensory input fails to match that prediction. Some scientists believe the brain interprets this mismatch as a sign of neurotoxin exposure, triggering vomiting as a defensive response.
Susceptibility varies widely. Children tend to be more affected than adults, possibly because they have not yet adapted to certain kinds of movement, and research generally suggests women are more susceptible than men. One study estimated that genetics account for 57% to 70% of a person's susceptibility. Kristen Steenerson, a vestibular neurologist at Stanford University School of Medicine, said people with migraines, particularly vestibular migraines involving vertigo or dizziness, are more prone to motion sickness and may react even to mild triggers such as watching an action film or unloading a dishwasher.
What helps
Over-the-counter antihistamines such as Dramamine and Bonine are effective when taken before symptoms start, though they can cause drowsiness, Steenerson said. A scopolamine patch worn behind the ear helps some people but can cause dry mouth and is not recommended for children or older adults. Last year, the US Food and Drug Administration approved a new prescription drug, Nereus, which targets different brain receptors and may cause fewer side effects, according to Phillips.
Behavioural strategies can also help. Driving rather than riding as a passenger tends to reduce symptoms, since it puts a person in control of their environment, while passengers are advised to sit toward the centre of a vehicle and keep their eyes fixed on the road, Steenerson said. Erich Voigt, an otolaryngologist at NYU Langone Health, recommends sitting near the centre of aircraft and staying above deck on boats, where the horizon remains visible. Controlled breathing, fresh air, calming music and scents such as rose or lemon may also ease symptoms, though evidence for ginger and other supplements remains mixed, and most studies suggest acupressure bracelets and motion sickness glasses work no better than a placebo.
For persistent cases, a physical therapist specialising in neurology or vestibular rehabilitation can help identify specific triggers and build tolerance over time through gradual, controlled exposure. Steenerson said this approach can outperform many other treatments. "It takes time and it's unpleasant," she said, but with commitment it can work "really, really well."
Understanding personal triggers can also help people manage the condition long-term. Steenerson said she becomes ill in cars yet enjoys roller coasters, while Phillips said his own sailboat does not trigger the same severe symptoms he experienced on a research vessel. Most people can manage motion sickness with planning, Phillips said, though "there's some things that are just, you know, overwhelming for some people."
Source: The New York Times
