Vomiting, medically called emesis, is the forceful ejection of material from the stomach through the mouth. It is a symptom rather than a disease and can contain recently eaten food, stomach fluids, bile or, in some conditions, blood. The action is often sudden and unpleasant and may be accompanied by nausea, sweating and increased salivation. For basic anatomical context see the stomach and the mouth, structures directly involved in the process.

Common causes and triggers

  • Infections of the gut or systemic infections (viral gastroenteritis).
  • Foodborne intoxication or contaminated food and drink (food poisoning).
  • Sensory triggers such as strong or unpleasant odors and tastes, or motion sickness.
  • Medications, alcohol (excess alcohol) and recreational drugs.
  • Obstruction of the gastrointestinal tract, for example a block in the small intestine (small intestine obstruction), which prevents passage of stomach contents.
  • Centrally mediated causes including raised intracranial pressure or injury to the brain.
  • Metabolic problems, pregnancy (early pregnancy nausea and vomiting), and psychological causes including deliberate, self-induced vomiting (purging) related to eating disorders.

The body usually produces vomiting through coordinated reflexes. Sensors in the gut and blood detect irritants or toxins and signal the brain’s vomiting center and the chemoreceptor trigger zone. Signals are transmitted by cranial nerves and the autonomic nervous system, producing reverse intestinal movements, relaxation of the lower esophageal sphincter, and strong contractions of the diaphragm and abdominal muscles to expel contents.

Complications and notable features

  • Dehydration and electrolyte imbalance are common risks with repeated vomiting; severe dehydration can be life-threatening without treatment (dehydration).
  • Inhalation (aspiration) of vomit into the lungs can cause pneumonia or airway obstruction.
  • Forceful or prolonged vomiting may tear the mucosa of the esophagus (Mallory–Weiss tear) or erode tooth enamel over time.
  • Vomiting of blood (hematemesis) suggests bleeding higher in the digestive tract and requires urgent evaluation.

Treatment focuses on the underlying cause, symptom control and preventing complications. For mild, short-lived vomiting, oral rehydration with clear fluids and rest are often sufficient. Antiemetic medications may be used to reduce nausea and allow oral intake. In more severe cases, intravenous fluids and electrolyte replacement are necessary. Ingestion of toxic substances is a special situation: historically, inducing vomiting was sometimes used to remove poisons, but current medical advice varies and professional guidance should be sought before attempting any decontamination; if poisoning is suspected contact emergency services or a poison control center (poison).

When to seek immediate medical attention: persistent vomiting for more than 24 hours, signs of severe dehydration (very little urine, dizziness, dry mouth), bloody or coffee-ground vomit, severe abdominal pain, high fever, or altered mental status. Suspected brain injury with vomiting also requires urgent care (brain). For mechanical causes such as suspected intestinal blockage, rapid medical evaluation is important (small intestine obstruction).

Prevention and supportive measures include proper food handling to reduce food poisoning, limiting alcohol and irritant substances, motion-sickness strategies, and medical supervision for medication side effects. Chronic or self-induced vomiting connected with eating disorders needs coordinated medical and mental health treatment. Although vomiting is common and often self-limited, persistent, severe, or complicated cases require professional assessment to avoid harm and treat underlying disease.

For more general anatomy and care information see resources on the stomach and emergency management of dehydration.