(See also Overview of Acute Viral Hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is inflammation of the liver caused by infection with one of the five hepatitis viruses. In most people, the inflammation begins suddenly and lasts only a few weeks. Symptoms... read more and Overview of Chronic Hepatitis Overview of Chronic Hepatitis Chronic hepatitis is inflammation of the liver that lasts at least 6 months. Common causes include hepatitis B and C viruses and certain drugs. Most people have no symptoms, but some have vague... read more .)
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 Overview of Acute Viral Hepatitis Acute viral hepatitis is inflammation of the liver caused by infection with one of the five hepatitis viruses. In most people, the inflammation begins suddenly and lasts only a few weeks. Symptoms... read more ) resolve on their own, but some progress to chronic hepatitis Overview of Chronic Hepatitis Chronic hepatitis is inflammation of the liver that lasts at least 6 months. Common causes include hepatitis B and C viruses and certain drugs. Most people have no symptoms, but some have vague... read more .
Causes of Hepatitis
Hepatitis commonly results from
A virus, particularly one of the five major hepatitis viruses—A, B, C, D, or E
Nonalcoholic fatty liver disease Fatty Liver (NAFLD), including nonalcoholic steatohepatitis Fatty Liver (NASH)
Use of certain drugs, such as isoniazid (used to treat tuberculosis)
Less commonly, hepatitis results from a reaction of the immune system that causes inflammation of the liver (autoimmune hepatitis), genetic liver disorders, and other infections (such as infectious mononucleosis Infectious Mononucleosis Epstein-Barr virus causes a number of diseases, including infectious mononucleosis. The virus is spread through kissing. Symptoms vary, but the most common are extreme fatigue, fever, sore throat... read more 
, herpes simplex Herpes Simplex Virus (HSV) Infections Herpes simplex virus infection causes recurring episodes of small, painful, fluid-filled blisters on the skin, mouth, lips (cold sores), eyes, or genitals. This very contagious viral infection... read more 
, or cytomegalovirus infection Cytomegalovirus (CMV) Infection Cytomegalovirus infection is a common herpesvirus infection with a wide range of symptoms: from no symptoms to fever and fatigue (resembling infectious mononucleosis) to severe symptoms involving... read more ).
