Nausea is the sensation of unease and discomfort from the stomach, with the sufferers feeling that they may vomit. Nausea can be acute and short-lived, or it can be prolonged. When prolonged, it is a debilitating symptom. Nausea (and vomiting) can be psychological or physical in origin. It can originate from problems in the brain or organs of the upper gastrointestinal tract (esophagus, stomach, small intestine, liver, pancreas, and gallbladder). It also may be caused by pain, motion,
medications and diseases of many non-gastrointestinal organs of the body. Therefore, the diagnosis of the cause of prolonged nausea may not be easy. All stimuli that cause nausea work via the vomiting center in the brain which gives rise to the sensation of nausea and coordinates the physical act of vomiting.
Nausea is a symptom of many conditions, including motion sickness, morning sickness during pregnancy, viral infections, and other diseases. It is also a side effect of many drugs. In medicine, nausea is a particular problem during some chemotherapy regimens and following general anaesthesia. Nausea is also a common symptom of pregnancy. Whilst short-term nausea and vomiting are generally harmless, they may sometimes indicate a more serious disease. When associated with prolonged vomiting, it may cause dangerous levels of dehydration. Symptomatic treatment for nausea and vomiting may include short-term avoidance of solid food. This is usually easy as nausea is nearly always associated with loss of apetite (anorexia). Dehydration may require rehydration with oral or intravenous electrolyte solutions. Oral rehydration is safer and simpler in most cases. There are many antiemetic drugs to treat nausea, although the researchers continue to look for more effective treatments.
Nausea is not a disease, but a symptom of many different disorders. It is caused by problems in any one of three parts of the body. Many different abdominal conditions can cause nausea. Common abdominal causes of nausea include inflammation of the liver (hepatitis) or pancreas (pancreatitis); intestinal blockage or stretching; gastroesophageal reflux (GERD); irritation of the stomach, intestinal lining, appendix or pelvic organs; inflammation of the kidney; and gallbladder problems. The most common abdominal illnesses that result in nausea are viral infections (gastroenteritis). Nausea also can be caused by constipation and normal menstruation. Nausea is common with migraine headaches, brain tumors, stroke, bleeding into or around the brain, and meningitis (inflammation or infection of the membranes covering the brain). It can be a symptom of glaucoma, resulting from pressure on the nerves at the back of the eye. It sometimes is a brain reaction triggered by pain, significant emotional distress, or exposure to unpleasant sights or odors. Nausea can be related to vertigo, a dizzy sensation of spinning, moving or falling when you are not moving. Common conditions that cause vertigo include motion sickness (triggered by repeated movements in different directions inside a car, boat, train, plane or amusement ride), viral infections of the inner ear (labyrinthitis), sensitivity to position change (benign positional vertigo), and certain brain or nerve tumors.
Nausea does not always require treatment, but sometimes treatment is helpful. Drink beverages that settle the stomach, such as ginger ale or chamomile tea. Avoid caffeinated colas, coffees and teas; caffeinated drinks promote the production of stomach acid. Drink clear liquids to avoid dehydration (if vomiting is associated with nausea). Eat small, frequent meals to allow the stomach to digest foods gradually. Eat foods that can absorb stomach acid, such as crackers or unbuttered bread. Avoid spicy foods and fried foods. Eat bland foods that are digested easily, such as rice, chicken soup and bananas.
Some over-the-counter medications can help to relieve nausea. Chewable or liquid antacids, bismuth sub-salicylate (Pepto-Bismol) or a solution of glucose, fructose and phosphoric acid (Emetrol) provide relief by coating the stomach lining and neutralizing stomach acid. Dimenhydrinate (Dramamine) or meclizine hydrochloride (Bonine, Dramamine II) are helpful for treating or preventing motion sickness and are thought to block receptors in the brain that trigger vomiting.