Nausea

A 1681 painting depicting a person vomiting.
ICD-10	R11.
ICD-9	787.0

Nausea (Latin nausea, from Greek ναυσίη, nausiē, "seasickness" "wamble" ^[1]), is a sensation of unease and discomfort in the upper stomach with an urge to vomit.^[2] 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.

[edit] Definition

Nausea is the painless sensation of feeling like one is going to vomit.^[2][3]

[edit] Differential diagnosis

The causes of nausea are many. One organization listed 700 in 2009.^[4] Gastrointestinal infections (37%) and food poisoning are the two most common causes.^[2][5] While side effects from medications (3%) and pregnancy are also relatively frequent.^[2][5] In 10% of people the cause remains unknown.^[5]

[edit] 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.^[3] It is due to toxins produced by bacteria in the food.^[3]

[edit] Medications

Most medications can potential cause nausea.^[3] Some of the most frequently associated include chemotherapy regimens and general anaesthetic agents.

[edit] Pregnancy

Nausea or "morning sickness" is a common symptom of pregnancy. In the first trimester nearly 80% of women have some degree of nausea.^[6] Pregnancy therefore should be considered in any women of child bearing age.^[3] While usually it is mild and self limiting severe cases known as hyperemesis gravidarum may require treatment.^[7]

[edit] Disequilibrium

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

[edit] 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.^[2]

[edit] Diagnostic approach

Often no investigations are needed, however basic lab tests may be appropriate.^[2] If a bowel obstruction is considered abdominal x-rays maybe useful.^[2]

[edit] Treatment

If the dehydration is present, rehydration with oral electrolyte solutions is preferred.^[2] If this is not effective intravenous rehydration maybe required.^[2]

[edit] Medications

Dimenhydrinate (gravol) is an inexpensive an effective medication for preventing postoperative nausea and vomiting.^[8] In certain people cannabinoids may be effective in reducing chemotherapy associated nausea and vomiting.^[9][10] Ondansetron (Zofran) is effective for nausea and vomiting however is expensive.^[3] Pyridoxine or metoclopramide are the first line treatments for pregnancy related nausea and vomiting.^[7]

[edit] Complementary medicine

Acupuncture is effective for the prevention of post operative nausea and vomiting.^[11] 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.^[12] It however may be effective in pregnancy associated nausea and vomiting.^[13]

[edit] 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.

[edit] Epidemiology

Nausea and or vomiting is the main complaint in 1.6% of visits to family physicians in Australia.^[5] However only 25% of people with nausea visit their family physician.^[2] It is most common in those 15 - 24 years old and less common in other ages.^[5]

[edit] References