About Vomiting

Vomiting is a common symptom that most people experience many times throughout their lives. Most vomiting is a result of minor illnesses, but occasionally it indicates a more serious problem. Vomiting may also be caused by anxiety, pregnancy, or motion sickness, and is sometimes self-induced.

The Facts

• Involuntary vomiting may be caused by a wide variety of health conditions and other problems. Common causes include viral gastroenteritis ("stomach flu"), over-consumption of alcoholic beverages, early pregnancy, side effects from medication, and motion sickness. Less frequently, vomiting may be caused by serious health conditions such as metabolic disturbances, head injury and appendicitis. Self-induced vomiting is usually the result of an eating disorder, but may also be performed in an emergency when a poisonous substance has been ingested.

Function

• Vomiting is a biological mechanism that is triggered primarily when the stomach is irritated, as it frequently is when poisonous substances have been consumed. It is therefore believed to be a protective reflex to expel toxic substances before they have been absorbed into the bloodstream. It is unknown why conditions other than gastrointestinal irritation frequently lead to vomiting; the cause of morning sickness during early pregnancy is also poorly understood.

Significance

• Vomiting has a number of causes, some of which are innocuous; others are serious conditions and medical emergencies. If vomiting accompanies head injury, the likelihood of skull fracture is significantly higher and the injured person should be taken to a hospital at once. If vomiting is accompanied by dehydration, high fever, abdominal pain, or the vomitus contains blood, medical attention should be sought quickly. Self-induced vomiting, if performed in an attempt to lose weight or following a binge eating episode, is a clear sign of a serious eating disorder and should be treated as such.

Effects

• In general, vomiting is relatively harmless; however, very forceful, prolonged, or recurrent vomiting may lead to complications. Dehydration is the most common problem encountered, and severe vomiting may cause life-threatening electrolyte imbalances such as hypokalemia (low potassium levels). Recurrent vomiting may cause damage to the enamel of the teeth, particularly the inner surface of the upper central incisors.

Type

• Common vomiting generally occurs following preliminary symptoms such as nausea, sweating, weakness, and excess salivation. Retching, or "dry heaves," often immediately precedes vomiting; the stomach's contents are expelled into the esophagus but do not pass into the mouth. Projectile vomiting is when vomitus is expelled with great force and without any signs that the person is about to vomit. The term "coffee grounds emesis" refers to vomitus that includes congealed blood, which visually resembles wet coffee grounds.