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Medically reviewed by Last updated on Feb 15, 2024.

What is Hepatitis?

Harvard Health Publishing

Hepatitis is inflammation of the liver. There are several types of hepatitis. The disease has several causes.

One cause of hepatitis is infection. Most cases of infectious hepatitis in the United States are caused by hepatitis A, B or C virus.

An infection with one of these viruses might not cause any symptoms. Or it might cause only a mild, flu-like illness. Hepatitis A is usually a mild short-term illness. But hepatitis B and C often cause long-term (chronic) infections.

Hepatitis D is uncommon. Hepatitis E occurs primarily in underdeveloped countries.

Depending on the hepatitis virus, the infection can be spread in a number of ways. These include:

Improved blood screening techniques have greatly reduced the risk of catching hepatitis B or C from blood transfusions.

Hepatitis has many other possible causes. These include:


Symptoms of hepatitis vary. They depend on the cause of the illness and how much the liver has been damaged.

In mild cases, many people do not have any symptoms. Or they may have flu-like symptoms. These can include:

In more severe cases, chemicals from the liver can build up in the blood and urine. This can cause:


Your doctor will ask about your:

Your doctor will examine you. He or she will look for signs of jaundice. Your doctor will also check for tenderness and swelling near your liver.

To confirm a hepatitis diagnosis, your doctor will order blood tests. You may also need other tests, such as a liver biopsy.

Expected Duration

How long hepatitis lasts depends on:

Most previously healthy people who develop hepatitis A recover completely in about one month.

A small percentage of adults who get hepatitis B develop chronic hepatitis. This is much more likely to happen in babies and young children. A small number of those with chronic hepatitis eventually develop cirrhosis or liver cancer. Cirrhosis is scarring of the liver that results in poor liver function.

More than three-quarters of people infected with hepatitis C develop chronic infection. Prior to antiviral therapy for hepatitis C, about one in five developed cirrhosis. Today the prognosis has improved dramatically. Cirrhosis increases the risk of liver cancer.

Hepatitis caused by bacterial or parasitic infections usually improves when the infection is treated.

Medication and alcohol related hepatitis usually improve when the medication or alcohol is withdrawn. But liver damage may persist.


You can reduce your chance of getting viral hepatitis. Follow these basic guidelines:


Sudden onset of severe hepatitis can be life threatening. It often requires treatment in the hospital.

Most people with hepatitis A do not require hospitalization unless they have persistent vomiting.

Anyone suspected of having acetaminophen-related hepatitis should immediately go to an emergency room. There is an antidote. But it must be given soon after the drug is ingested.

Certain types of hepatitis are chronic (persistent), for example hepatitis B and C and autoimmune hepatitis. A variety of medications are available to treat chronic hepatitis.

When To Call a Professional

Call your doctor if you have symptoms of hepatitis. Also call if you believe you have been exposed to someone with hepatitis.

If you are planning to travel abroad, ask your doctor whether you need hepatitis immunization before your trip.


Most people with either hepatitis A or B recover without treatment.

Many people with hepatitis C develop chronic hepatitis. A smaller number of those with hepatitis B develop chronic hepatitis.

Some people with hepatitis B become lifelong carriers. They can spread the hepatitis infection to others. People with chronic hepatitis C also are infectious. They can spread the virus through blood-to-blood contact.

Additional Info

American Liver Foundation

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.