Hepatitis is inflammation of the liver.
Topic Resources
Hepatitis is common throughout the world.
Hepatitis can be
Acute (short-lived)
Chronic (lasting at least 6 months)
Most cases of acute hepatitis caused by a virus (acute viral hepatitis) resolve on their own, but some progress to chronic hepatitis.
(See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.)
Did You Know...
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Causes of Hepatitis
Hepatitis commonly results from
A virus, particularly 1 of the 5 major hepatitis viruses—A, B, C, D, or E
Fatty liver due to abnormal metabolism
Use of certain medications, such as isoniazid (used to treat tuberculosis) Use of certain medications, such as isoniazid (used to treat tuberculosis)
Metabolism is the process that converts food into energy; uses food to produce molecules that maintain the body such as proteins, carbohydrates, and fats; and gets rid of the body's waste products. Abnormal metabolism in liver cells leads to buildup of fat and inflammation. This is called metabolic dysfunction-associated liver disease (MASLD), which can lead to metabolic dysfunction-associated steatohepatitis (MASH). (MASLD was formerly called nonalcoholic fatty liver disease [NAFLD], and MASH was formerly called nonalcoholic steatohepatitis [NASH].)
Less commonly, hepatitis results from a reaction of the immune system that causes inflammation of the liver (autoimmune hepatitis), genetic liver disorders, and other viral infections (such as infectious mononucleosis, herpes simplex, or cytomegalovirus infection). SARS-CoV-2 infection (COVID-19) can cause hepatitis that is usually mild. The severity of liver inflammation tends to correlate with the severity of COVID-19, but mild liver inflammation can develop even when the person has no symptoms of COVID-19.
The Hepatitis Viruses
Transmission | Symptoms and Prognosis | Prevention |
|---|---|---|
Ingestion of something contaminated with the stool of an infected person, usually because of poor hygiene or inadequate sanitation (called the fecal-oral route). | Usually no symptoms in young children Usually in older children and adults, typical symptoms of acute hepatitis (poor appetite, nausea, vomiting, and often jaundice) Usually complete recovery Does not become chronic | Use of good hygiene when handling food and avoidance of contaminated water Vaccination against hepatitis A for all children and for adults likely to be exposed to the infection If people are exposed to hepatitis A, hepatitis A vaccine or standard immune globulin* |
Less easily transmitted than hepatitis A Contact with blood and other body fluids (such as semen, vaginal fluids, or saliva)—as occurs during the following:
| Generally more serious than hepatitis A and occasionally fatal More severe symptoms when people with hepatitis B also have hepatitis D Joint pains and itchy red hives on the skin (wheals) in addition to typical symptoms of acute hepatitis Can become chronic, with increased risk of liver cancer | Avoidance of high-risk behavior, such as sharing needles to inject drugs and having several sex partners Vaccination against hepatitis B for all children (starting at birth) and for people likely to be exposed to the infection If people are exposed to hepatitis B (including babies born to mothers with hepatitis B), hepatitis B immune globulin* and the vaccineIf people are exposed to hepatitis B (including babies born to mothers with hepatitis B), hepatitis B immune globulin* and the vaccine |
Contact with blood and other body fluids (such as semen, vaginal fluids, or saliva)—as occurs during the following:
| At first, usually mild or no symptoms but sometimes alternating between mild and more severe symptoms Becomes chronic in about 75% of people, with increased risk of severe scarring of the liver (cirrhosis) and liver cancer, but usually only if cirrhosis has developed first | Avoidance of high-risk behavior, such as sharing needles to inject drugs and getting tattoos and body piercings No vaccine currently available |
Contact with blood and other body fluids (such as semen, vaginal fluids, or saliva)—as occurs during the following:
| Occurs only as a coinfection with hepatitis B and usually makes the hepatitis B infection more severe | Same as for hepatitis B:
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Ingestion of something contaminated with the stool of an infected person (called the fecal-oral route), usually because of poor hygiene or inadequate sanitation Occasionally consumption of meat from an infected animal | Severe symptoms, especially in pregnant women Does not usually become chronic | Vaccination against hepatitis E (currently available only in China) |
* Standard immune globulin is a preparation containing antibodies obtained from the blood (plasma) of people with a normal immune system. It is used to treat a variety of diseases. Hepatitis B immune globulin contains antibodies obtained from the blood of people who have high levels of antibodies to hepatitis B. It is given by injection into a muscle or into a vein.* Standard immune globulin is a preparation containing antibodies obtained from the blood (plasma) of people with a normal immune system. It is used to treat a variety of diseases. Hepatitis B immune globulin contains antibodies obtained from the blood of people who have high levels of antibodies to hepatitis B. It is given by injection into a muscle or into a vein. | ||
† A pregnant woman infected with hepatitis B or hepatitis C can transmit the virus to her baby. | ||
