Nausea and Vomiting

Nausea is a diffuse sensation of unease and discomfort, sometimes described as an urge to vomit, that can be felt in the chest, abdomen, or throat and can be debilitating if it persists; more than thirty different clinical definitions of the sensation have been proposed. Vomiting is the physical act that often follows nausea, and while the two are closely related they are distinct: nausea is a subjective feeling and vomiting is the forceful expulsion of stomach contents. Together they arise from a wide range of causes, including gastrointestinal infection, which accounts for roughly thirty-seven percent of acute cases, food poisoning, medication side effects, pregnancy-related morning sickness, motion sickness, dizziness, migraine, anxiety, dehydration, and sleep deprivation, with chemotherapy and certain other drugs also frequent culprits. Nausea goes undiagnosed in an estimated ten percent of cases, and doctor visits for it become markedly less common with age. Most episodes resolve within hours to a day, but prolonged vomiting carries a real risk of dehydration and dangerous electrolyte imbalance.