Nausea

Nausea (Latin nausea, from Greek ναυσίη, nausiē, "seasickness" "wamble"), is a sensation of unease and discomfort in the upper stomach with an urge to vomit. An attack of nausea is known as a qualm.

The most common cause is gastroenteritis ( a stomach infection ) or food poisoning but nausea also frequently occurs as a medication side effect and in pregnancy. A number of medication exist that improve symptoms including: dimenhydrinate, metoclopramide, and ondansetron.

Definition

Nausea is the painless sensation of feeling like one is going to vomit.

Differential diagnosis

The causes of nausea are many. One organization listed 700 in 2009. Gastrointestinal infections (37%) and food poisoning are the two most common causes. While side effects from medications (3%) and pregnancy are also relatively frequent. In 10% of people the cause remains unknown.

Food poisoning

Food poisoning usually causes an abrupt onset of nausea and vomiting one to six hours after ingestion of contaminated food and lasts for one to two days. It is due to toxins produced by bacteria in the food.

Medications

Most medications can potentially cause nausea. Some of the most frequently associated include chemotherapy regimens and general anaesthetic agents.

Pregnancy

Nausea or "morning sickness" is a common symptom of pregnancy. In the first trimester nearly 80% of women have some degree of nausea. Pregnancy therefore should be considered in any women of child bearing age. While usually it is mild and self limiting severe cases known as hyperemesis gravidarum may require treatment.

Disequilibrium

A number of conditions involving balance such as motion sickness and vertigo can lead to nausea and vomiting.

Potentially serious

While most causes of nausea are not serious some serious causes do occur. These include: diabetic ketoacidosis, surgical problems (pancreatitis, small bowel obstruction,meningitis, appendicitis, cholecystitis), Addisonian crisis, and hepatitis among others.

Diagnostic approach

Often no investigations are needed, however basic lab tests may be appropriate. If a bowel obstruction is considered abdominal x-rays maybe useful.

Treatment

If the dehydration is present, rehydration with oral electrolyte solutions is preferred. If this is not effective intravenous rehydration maybe required.

Medications

Dimenhydrinate (gravol) is an inexpensive an effective medication for preventing postoperative nausea and vomiting. In certain people cannabinoids may be effective in reducing chemotherapy associated nausea and vomiting. Ondansetron (Zofran) is effective for nausea and vomiting however is expensive. Pyridoxine or metoclopramide are the first line treatments for pregnancy related nausea and vomiting.

Complementary medicine

Acupuncture is effective for the prevention of post operative nausea and vomiting. The spices ginger and peppermint have been used for centuries as traditional remedies for nausea. Evidence, however, does not support gingers effectiveness in post op nausea and vomiting. It however may be effective in pregnancy associated nausea and vomiting.

Prognosis

While short-term nausea and vomiting are generally harmless, they may sometimes indicate a more serious condition. When associated with prolonged vomiting, it may lead to dehydration and/or dangerous electrolyte imbalances.

Epidemiology

Nausea and or vomiting is the main complaint in 1.6% of visits to family physicians in Australia. However only 25% of people with nausea visit their family physician. It is most common in those 15 – 24 years old and less common in other ages.