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What Is Hepatitis?

Many people mistakenly think that hepatitis means viral hepatitis, and that all forms of hepatitis are contagious. Actually, the word hepatitis is a catch-all term that refers to any inflammation of the liver -- the irritation or swelling of liver cells from any cause.

Hepatitis can be acute (inflammation of the liver that lasts less than six months) or chronic (inflammation of the liver that lasts more than six months) and has many different causes. It can be caused by a group of viruses known as the hepatitis viruses, including A, B, C, D, and E. Other viruses may also cause it, such as those that cause mononucleosis (the Epstein-Barr virus) or chickenpox (the varicella virus). Hepatitis also refers to inflammation of the liver caused by drugs and alcohol abuse or toxins in the environment. In addition, people can develop hepatitis from other things, such as fat buildup in the liver (called fatty liver hepatitis or NASH – nonalcoholic steatohepatitis), trauma, or an autoimmune process in which a person's body makes antibodies that attack the liver (autoimmune hepatitis).

Viral hepatitis is common. Thousands of cases are reported to the CDC each year, but researchers estimate that the true number of people in the United States who have either acute or chronic hepatitis is much higher than what is reported. This is because most people with hepatitis are not diagnosed. Many people mistake their symptoms as the flu instead of hepatitis.

The five hepatitis viruses can be transmitted in different ways, but they all have one thing in common: They infect the liver and cause it to become inflamed.

Many people with hepatitis recover with a lifelong immunity to the disease, but some people with hepatitis die in the acute phase. Hepatitis B and C may progress to chronic hepatitis, in which the liver remains inflamed for more than six months. This can lead to cirrhosis, liver cancer, and sometimes death.


What Causes Hepatitis?

Although their effects on the liver and the symptoms they produce can be similar, the various forms of hepatitis are contracted in different ways. In the case of viral hepatitis, the severity and duration of the disease are determined by virus that caused it.

What Puts You at Risk?

See how viral hepatitis spreads. Discover where the risk is greatest.
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