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Hepatitis A, Acute

By Anna E. Rutherford, MD, MPH, Assistant Professor of Medicine;Clinical Director of Hepatology, Harvard Medical School;Brigham and Women’s Hospital

Acute hepatitis A is inflammation of the liver that is caused by the hepatitis A virus and that lasts less than 6 months.

  • Hepatitis A is usually spread when people ingest something that has been contaminated by the stool of an infected person.

  • Hepatitis A causes typical symptoms of viral hepatitis (including loss of appetite, a general feeling of illness, and jaundice) in older children and adults but may cause no symptoms in young children.

  • Doctors diagnose hepatitis A based on blood tests.

  • Vaccination against hepatitis A is recommended for all children and for adults likely to be exposed to the infection or to develop severe complications of the infection.

  • There is no specific treatment for hepatitis A, but most people recover completely.

Hepatitis A is the most common cause of acute viral hepatitis. It is particularly common among children and young adults. Hepatitis A does not become chronic. That is, the infection does not last longer than 6 months.

In the United States, about 2,500 cases of hepatitis were reported in 2014—a decrease from about 25,000 to 35,000 cases each year before the hepatitis A vaccine became available in 1995. In some countries, more than 75% of adults have been exposed to the hepatitis A virus.

Transmission of hepatitis A

Hepatitis A is usually spread when people ingest the virus after touching an object or consuming food or drinks that are contaminated by the stool of an infected person (called the fecal-oral route). Spread usually occurs because of poor hygiene—for example, when an infected person prepares food with unwashed hands. Shellfish taken from waters where raw sewage drains are sometimes contaminated and can cause infection when they are eaten raw.

Hepatitis A is sometimes spread in day care centers, where caregivers and children can come in contact with infected stool in diapers.

People can spread the virus before they develop symptoms—before they know they are infected.

Epidemics, usually linked to contamination of water supplies by stool, are common, especially in developing countries.

People with hepatitis A do not become carriers. Carriers are people who have and can transmit the virus but have no symptoms of the infection.


Most older children and adults with hepatitis A have typical symptoms of acute hepatitis. These symptoms include

  • Loss of appetite

  • A general feeling of illness (malaise)

  • Vomiting

  • Pain in the upper right part of the abdomen (where the liver is located)

  • Dark-colored urine

  • Jaundice (yellowing of the skin and the whites of the eyes) in about 70%

About 70% of children under 6 years old have no symptoms, and those that have symptoms rarely have jaundice.

Symptoms of cholestasis (a reduction or stoppage of bile flow)—such as pale stools and overall itchiness—may develop.

Symptoms usually disappear after about 2 months but may continue or recur for up to 6 months.

Hepatitis A does not cause severe scarring of the liver (cirrhosis). Hepatitis A rarely becomes severe (fulminant). Such cases are rarer than with hepatitis B.

Recovery from the acute hepatitis A is usually complete.


  • Blood tests

Doctors suspect hepatitis based on typical symptoms, such as jaundice.

Testing for hepatitis A usually begins with blood tests to determine how well the liver is functioning and whether it is damaged (liver function tests). Liver function tests involve measuring the levels of liver enzymes and other substances produced by the liver. These tests may help establish or exclude the diagnosis of hepatitis, identify the cause, and determine the severity of liver damage.

Blood tests are also done to help doctors identify which hepatitis virus is causing the infection. These tests can detect the following:

  • Antibodies produced by the person's immune system in response to the specific hepatitis virus

  • Antigens of the specific hepatitis virus (antigens are any substances that can trigger an immune response in the body)


Using good hygiene when handling food can help prevent the spread of hepatitis A. People should wash their hands with soap and water after using the bathroom, after changing a diaper, and before handling food.

Avoiding contaminated water supplies is also important. People need to be particularly careful when they travel to areas where sanitation may be inadequate.

Vaccination against hepatitis A is recommended for all children (see Figure: Vaccinating Infants and Children). It is also recommended for adults at high risk of exposure to the infection:

  • Travelers to parts of the world where hepatitis A is widespread

  • People who work in diagnostic or research laboratories that handle hepatitis A virus

  • People with chronic liver disorders or bleeding disorders

  • Men who have sex with men

  • People who use illicit drugs (who are often infected for reasons other than drug use)

People with chronic liver disorders (including chronic hepatitis C) should be vaccinated against hepatitis A because they may have an increased risk of developing fulminant hepatitis and liver failure due to hepatitis A virus.

Prevention after exposure to hepatitis A

Preventive measures are recommended for family members and close contacts of people with hepatitis A because they have been exposed to the infection (called postexposure prophylaxis).

If people who have not been previously vaccinated are exposed to hepatitis A, they are given one of the following:

  • Healthy people aged 1 to 40 years: One dose of the hepatitis A vaccine

  • People who are over 40 or who have a weakened immune system or chronic liver disease: Standard immune globulin

Standard immune globulin is a preparation containing antibodies obtained from the blood of people with a normal immune system. This treatment prevents or decreases the severity of infection.


  • General measures

There is no specific treatment for hepatitis A.

People with hepatitis A should not drink alcohol because it can damage the liver further. There is no need to avoid certain foods or limit activity.

If itching occurs, cholestyramine, taken by mouth, is often effective.

Most people can safely return to work after jaundice resolves.

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