The term "vomiting" describes the forceful expulsion of the contents of the stomach via the mouth or sometimes the nose, also known of as emesis. The causes of vomiting are as wide ranging as those for nausea and include anything from food poisoning or gastritis to head injuries and brain cancer. Nausea is the discomfort that is felt before vomiting but not all nausea actually results in vomiting.
Regurgitation is a different condition from vomiting and the term regurgitation usually means expulsion of the undigested food from the food pipe or esophagus into the mouth, with none of the forceful expulsion or discomfort that is associated with nausea. The two conditions are different as are their underlying causes.
Causes of vomiting
Vomiting, like nausea, is a symptom rather than a disease in itself. Sometimes it is the body's only way to eject a harmful or poisonous substance. Common causes of vomiting include:
Gastrointestinal disorders such as gastroesophageal reflux disease, peptic ulcer, celiac disease, Crohn's disease, irritable bowel syndrome, pancreatitis and liver disease
Motion sickness and disorders of the inner ear
Morning sickness associated with pregnancy
Medications including cancer chemotherapy
People need immediate treatment for vomiting if they have been vomiting continuously for more than 24 hours, have been unable to keep down fluids for 12 hours or more, are expelling green, brown or red vomit, or are expelling undigested foods while suffering from severe abdominal pain. Prolonged vomiting may lead to dehydration and lack of essential electrolytes in the body.
Diagnosis and treatment
Vomiting is a symptom of an underlying condition that needs to be diagnosed for treatment to be effective. Medications called antiemetics may help reduce nausea and vomiting by speeding up the emptying of the gut to relieve the nausea and uncomfortable feeling of fullness in the stomach. Examples include metoclopramide and domperidone. Severe vomiting due to cancer chemotherapy and anaesthetic agents may be relieved with the use of ondansetron, promethazine, dimenhydrinate, dexamethasone or droperidol. Pregnancy induced vomiting and nausea may be relieved with the use of doxylamine.