Nausea is an abdominal discomfort or queasiness that may be accompanied by vomiting (the forceful expulsion of stomach contents through the mouth).

Bouts of nausea and vomiting are common, especially in children. They usually subside quickly but can lead to dehydration, malnutrition and other complications if they continue over a prolonged period. Also, nausea and vomiting are symptoms of many conditions, some of which are serious in nature.

Nausea and vomiting may be accompanied by other symptoms, such as abdominal pain, fever and diarrhea. The symptoms experienced often provide clues about the cause of the nausea or vomiting.

There are many potential causes of nausea and vomiting, including certain medications (e.g., cancer drugs), gastrointestinal problems (e.g., foodborne illnesses) or other infections (e.g., pancreatitis), pregnancy, motion sickness and excessive consumption of alcohol. In addition, people with eating disorders such as bulimia nervosa may regularly induce vomiting after binge eating.

Nausea and vomiting may be treated in a variety of ways. Many cases require no treatment, or simply avoiding the food or medication causing the problem. Nausea can be controlled by drinking clear fluids and eating bland foods. Treatment for vomiting may include drinking fluids to avoid dehydration and taking antiemetics (medications to prevent or treat nausea and vomiting).

Some cases of nausea and vomiting can be prevented if the cause is known. For example, medication can be taken to prevent motion sickness.