Vomiting, << VOM uh tihng, >> is the action that expels the contents of the stomach through the mouth. It may indicate something as minor as overeating or as serious as approaching death. Vomiting can result from a wide variety of causes, including anxiety, bacterial infections, chemical irritation of the stomach, pregnancy, radiation, ulcers, unusual motion, or severe pain. Vomiting is usually preceded by nausea, an unpleasant sensation in the stomach area (see Nausea ).
Vomiting can cause death by suffocation in people who accidentally breathe in the vomitus (vomited material). This often occurs in intoxicated or unconscious people who vomit while lying on their backs. Repeated vomiting over many hours can cause death by dehydration, especially in infants (see Dehydration ). Vomiting after a head injury may indicate damage to the brain stem, and the person should receive treatment immediately in a hospital.
When a person vomits, the stomach contents are expelled by pressure created by the abdominal muscles and the diaphragm, a large muscle at the bottom of the ribs. This muscular activity is called retching. Retching involves movement of the diaphragm downward, contraction of the abdominal muscles, and squeezing of the stomach contents upward. A person vomits when retching becomes intense enough to force the stomach contents through the esophagus–the tube connecting the stomach and throat.
