vomit

Vomit, also known as emesis, is the forceful expulsion of the contents of the stomach through the mouth. It is a reflex action coordinated by the vomiting center in the brainstem, which receives signals from the stomach and intestines via nerves such as the vagus, as well as inputs from the chemoreceptor trigger zone and other brain regions. Vomiting may be preceded by nausea and retching, and the expelled material can vary in appearance from clear or watery to bile-stained or blood-tinged.

Causes of vomiting are broad and include infections of the stomach or intestines, food poisoning, and other gastrointestinal disorders; pregnancy-related nausea and hyperemesis; motion sickness and other vestibular disturbances; medication side effects or toxins; metabolic or endocrine disturbances; migraine, stress, or anxiety; and conditions that raise intracranial pressure or involve the central nervous system. Vomiting is also seen in infants with pyloric stenosis and in illnesses that cause dehydration. Regurgitation, by contrast, is the effortless return of stomach contents into the mouth without the strong rhythmic contractions typical of vomiting.

Management focuses on safety and symptom relief. For mild cases, small sips of water or oral rehydration solutions can prevent dehydration. Anti-emetic medicines may be used under medical guidance. Severe or prolonged vomiting can lead to dehydration, electrolyte imbalances, and, in some contexts, aspiration, so medical evaluation is advised if vomiting is persistent, if there is bile or blood in the vomit, if there is high fever, severe abdominal pain, confusion, or signs of dehydration, or if vomiting follows a head injury or in young children or older adults who are vulnerable.

Vomiting is a symptom that ranges from a benign, self-limited response to a sign of potentially serious illness, depending on the underlying cause and accompanying features.