Motion sickness, a condition historically linked to sailors coping with the movements of ships, now affects many individuals traveling by car, train, plane, and even in space. Symptoms often begin shortly after movement starts and can last for several hours after it ends. Initial signs typically include feelings of warmth, sweating, dizziness, headache, and fatigue, which may progress to nausea and vomiting.

The precise cause of motion sickness remains unclear, but research suggests it involves sensory conflicts within the body. According to Paul DiZio, a cognitive neuroscientist at Brandeis University, motion sickness arises when the brain receives inconsistent signals from different senses. For example, reading a book in a moving car causes the eyes to perceive a stationary page, while the inner ear detects motion. A prevalent theory posits that the brain forms a prediction of expected sensory input during movement, and sickness occurs when actual sensations differ from these predictions.

Susceptibility to motion sickness varies among individuals. Children are generally more prone than adults, and research indicates women may have a higher risk than men. The brain may interpret sensory mismatches as a sign of neurotoxins, triggering vomiting as a defensive response. Vestibular migraines, a condition characterized by vertigo or dizziness along with migraine symptoms, have also been linked to increased motion sickness susceptibility. Kristen Steenson, a vestibular neurologist at Stanford University School of Medicine, notes that these individuals may feel ill even during passive activities such as watching certain movies or reading while still.

Various treatments are available to prevent or reduce motion sickness. Over-the-counter antihistamines like Dramamine and Bonine are commonly used but are most effective if taken before exposure to motion. These medications can cause side effects such as drowsiness. Scopolamine patches, worn behind the ear, have also been effective for some but may produce side effects. Recently, the U.S. Food and Drug Administration approved Nereus, a prescription drug targeting different brain receptors to prevent vomiting, which may offer fewer adverse effects, according to James Phillips, a vestibular neurophysiologist at the University of Washington.

Behavioral strategies may also help mitigate symptoms. For instance, driving a car can reduce motion sickness because the driver controls the environment. Passengers are advised to focus on the road ahead. Positioning oneself at the center of a plane or above deck on a boat can help by providing a steady view of the horizon. Other measures such as controlled breathing, fresh air, and pleasant scents might offer some relief, though the scientific support for supplements, acupressure bracelets, and specialized motion sickness glasses is limited and often no better than placebo.

For those significantly affected by motion sickness, physical therapy specializing in neurology or vestibular rehabilitation may help improve tolerance by identifying specific triggers and training the body over time. While the process can be challenging, it can lead to substantial improvement, Steenson said. Nevertheless, some individuals face symptoms so severe that avoiding certain motions remains necessary.

Experts emphasize the importance of planning ahead to manage motion sickness effectively, although they acknowledge that no single approach works for everyone.