Nausea and vomiting in adults

[Zipporah Schumaker]

Nausea is an unpleasant feeling of needing to vomit. People also may feel dizziness, vague discomfort in the abdomen, and an unwillingness to eat.
Vomiting is a forceful contraction of the stomach that propels its contents up the esophagus and out the mouth. (See also Vomiting in Infants and Children.) Vomiting empties the stomach and often makes people with nausea feel considerably better, at least temporarily. Vomiting is quite uncomfortable and can be violent. Severe vomiting can project stomach contents many feet (projectile vomiting). Vomiting is not the same as regurgitation, which is the spitting up of stomach contents without forceful abdominal contractions or nausea. For instance, people with achalasia or Zenker diverticulum may regurgitate undigested food without nausea.
Vomitus—the material that is vomited up—usually reflects what was recently eaten. Sometimes it contains chunks of food. When blood is vomited, the vomitus is usually red (hematemesis), but if the blood has been partly digested, the vomitus looks like coffee grounds. When bile is present, the vomitus is bitter and yellow-green.