Motion Sickness FAQ

I recently returned home from a two-week liveaboard dive trip. After experiencing some initial motion sickness while adapting to the motion of the boat, I had a wonderful trip. At the end of the trip, however, I felt like the dock was rocking when we disembarked. I was queasy and almost vomited. This feeling continued for nearly a week before resolving. Why did this happen?

While we cannot say with certainty what caused your symptoms, you may have been suffering from condition that's known by various names including land sickness, disembarkment syndrome and mal de debarquement syndrome (MdDS). This syndrome occurs when the brain, having adjusted to the constant movement of the ship, has essentially forgotten how to handle a solid surface beneath the feet. The body finds the sensations of being on firm ground unfamiliar and abnormal. The vestibular system, which controls the body's balance, is disrupted and typically takes a few hours to a few days to readjust to being on a nonmoving surface. Some individuals, however, report a much longer time for resolution. No test can definitively diagnose disembarkment syndrome; diagnosis is based on the exclusion of reasonable alternatives.

While the main symptoms are a persistent rocking sensation and a sense of imbalance, other symptoms may include dizziness, fatigue, migraines, depression, nausea, difficulty concentrating and confusion. Typically, the condition is more pronounced when the person is sitting or lying down. Unlike motion sickness, the symptoms of disembarkment syndrome may improve with motion such as walking or riding in a vehicle.

It is impossible to predict whether an individual will suffer from disembarkment syndrome after a cruise or voyage. Those who readily adjust to the motion of the sea seem to be more susceptible. Disembarkment syndrome is more common in women than men, but a specific hormonal tie has not been detected. To decrease the likelihood of disembarkment syndrome, start seasickness-prevention measures a few days before boarding a ship and continue them for a few days after returning to land.

According to the MdDS Balance Disorder Foundation, there is no treatment for the condition since it typically subsides on its own. Motion-sickness medications such as meclizine or scopolamine are not effective with MdDS. Instead, clonazepam, benzodiazepines or amitriptyline may be beneficial. Additionally, light physical activity such as walking or yoga, taking naps, and possibly acupuncture may help strengthen the vestibular system.

Resources for additional information include the National Institutes of Health, the National Organization for Rare Disorders and the MdDs Balance Disorder Foundation.