seasickness

Seasickness, or mal de mer, is a form of motion sickness caused by movement at sea. It arises when the vestibular system in the inner ear senses motion that conflicts with visual input, producing nausea and other symptoms. It is most common on rough seas or in small boats, but can occur on any vessel.

Symptoms include nausea, vomiting, dizziness, pallor, cold sweating, and fatigue. Headache, increased saliva, yawning, and a sense of imbalance may also occur. Symptoms typically begin within hours of exposure and often improve with time or when movement stops.

Causes and risk factors: Seasickness results from sensory mismatch between motion signals from the inner ear and the eyes. Risk is higher for first-time travelers, children, pregnant people, those prone to migraines, and individuals with anxious or vestibular predispositions. Reading or focusing on a fixed object while the vessel moves can worsen symptoms.

Management: Non-drug measures include resting in a well-ventilated area, getting fresh air, looking at the horizon, avoiding reading, staying hydrated, and eating light meals. Ginger, acupressure bands, and other complementary approaches are used by some. Pharmacologic options include antihistamines (dimenhydrinate, meclizine, cyclizine) and, for longer voyages, the scopolamine patch. These medicines can cause drowsiness or dry mouth; use as directed and consult a clinician if needed.

Prevention and prognosis: Preventive strategies include gradual exposure, selecting stable seating, avoiding alcohol, and taking medication before symptoms begin when appropriate. Seasickness usually resolves when motion ceases and often recurs with future sea travel, though many people acclimate over time.

When to seek care: Seek medical advice if vomiting leads to dehydration, if there is severe chest pain, confusion, fainting, or if symptoms persist after travel.