Viral hepatitis is an infection that causes liver inflammation and damage. Inflammation is swelling that occurs when tissues of the body become injured or infected. Inflammation can damage organs. Researchers have discovered several different viruses that cause hepatitis, including hepatitis A, B, C, D, and E.
Hepatitis A and hepatitis E typically spread through contact with food or water that has been contaminated by an infected person’s stool. People may also get hepatitis E by eating undercooked pork, deer, or shellfish.
Hepatitis B, hepatitis C, and hepatitis D spread through contact with an infected person’s blood. Hepatitis B and D may also spread through contact with other body fluids. This contact can occur in many ways, including sharing drug needles or having unprotected sex.
The hepatitis A and E viruses typically cause only acute, or short-term, infections. In an acute infection, your body is able to fight off the infection and the virus goes away.
The hepatitis B, C, and D viruses can cause acute and chronic, or long-lasting, infections. Chronic hepatitis occurs when your body isn’t able to fight off the hepatitis virus and the virus does not go away. Chronic hepatitis can lead to complications such as cirrhosis, liver failure, and liver cancer . Early diagnosis and treatment of chronic hepatitis can prevent or lower your chances of developing these complications.
When doctors can’t find the cause of a person’s hepatitis, they may call this condition non-A–E hepatitis or hepatitis X. Experts think that unknown viruses other than hepatitis A, B, C, D, and E may cause some cases of hepatitis. Researchers are working to identify these viruses.
Although non-A–E hepatitis is most often acute, it can become chronic.
The NIDDK would like to thank Raymond Chung, M.D., Massachusetts General Hospital; Adrian M. Di Bisceglie, M.D., Saint Louis University School of Medicine; Paul Martin, M.D., University of Miami Miller School of Medicine
