Hepatitis A

In this section:

• What is hepatitis A?
• How common is hepatitis A?
• Who is more likely to get hepatitis A?
• What are the complications of hepatitis A?
• What are the symptoms of hepatitis A?
• What causes hepatitis A?
• How do doctors diagnose hepatitis A?
• How do doctors treat hepatitis A?
• Can I prevent hepatitis A?
• How can I prevent spreading hepatitis A to others?
• What should I eat and drink if I have hepatitis A?
• Clinical Trials for Hepatitis A

What is hepatitis A?

Hepatitis A is a viral infection that causes short-term liver inflammation and damage. Inflammation is swelling that occurs when tissues of the body become injured or infected.

Viruses invade cells in your body. Many viruses cause infections that can spread from person to person. The hepatitis A virus typically spreads through consuming food or water that has been contaminated by stool from a person infected with hepatitis A.

Hepatitis A is an acute infection, which means it lasts only a short time. People usually get better without treatment after a few weeks. In rare cases, hepatitis A can be severe and lead to liver failure. Some people may need an emergency liver transplant to survive. Hepatitis A doesn’t lead to long-term liver damage or problems, such as cirrhosis.

The most effective way to protect yourself from hepatitis A is to get the hepatitis A vaccine. If you have hepatitis A, you can take steps to prevent spreading hepatitis A to others.

How common is hepatitis A?

Hepatitis A is less common in the United States than in some other parts of the world.

Hepatitis A worldwide

Hepatitis A is most common in areas where sanitation and access to clean water are limited. These areas include parts of Africa, Asia, Central and South America, and Eastern Europe.¹

Hepatitis A in the United States

After the hepatitis A vaccine became available in 1995, the number of infections per year went down by more than 95% over the next 20 years.²

In 2022, 2,265 cases of hepatitis A were reported.³ However, many hepatitis A cases aren’t reported.

Who is more likely to get hepatitis A?

People are more likely to get hepatitis A if they

• travel to countries where hepatitis A is common
• have sex with an infected person
• are men who have sex with men
• use illegal drugs, including injected and noninjected drugs
• experience homelessness
• live with or care for someone who has hepatitis A
• live with or care for a child recently adopted from a country where hepatitis A is common

People who travel to countries where hepatitis A is common are more likely to get hepatitis A.

What are the complications of hepatitis A?

People typically recover from hepatitis A without complications. In rare cases, hepatitis A may lead to liver failure. Liver failure due to hepatitis A is more common in older adults and in people who have another liver disease.⁴

What are the symptoms of hepatitis A?

Some people have symptoms 2 to 7 weeks after they have contact with the virus.⁴ People with hepatitis A typically get better without treatment after a few weeks. In some cases, symptoms can last up to 6 months.⁴ These symptoms may include

• darker urine color and lighter stool color
• diarrhea
• fatigue, or feeling tired
• fever
• joint pain
• loss of appetite, nausea, or vomiting
• pain in the abdomen
• yellowish eyes and skin, called jaundice

Some people infected with hepatitis A have no symptoms, including many children younger than age 6 years.³ Older children and adults are more likely to have symptoms.

What causes hepatitis A?

This type of hepatitis is caused by the hepatitis A virus, which spreads through contact with an infected person’s stool. Contact can occur by

• eating food made by an infected person who didn’t wash their hands after using the bathroom
• drinking untreated water or eating food washed in untreated water
• placing a finger or object in your mouth that has had contact with an infected person’s stool
• having close personal contact with an infected person, such as through sex or caring for someone who is ill

You can’t get hepatitis A from

• being coughed or sneezed on by an infected person
• sitting next to an infected person
• hugging an infected person

A baby can’t get hepatitis A from breast milk.⁵

How do doctors diagnose hepatitis A?

Doctors diagnose hepatitis A based on symptoms and a blood test.

A health care professional will take a blood sample from you and send the sample to a lab. The lab will check the blood for a specific type of antibody that develops soon after infection with the hepatitis A virus. If your blood has these antibodies, your doctor may diagnose you with acute hepatitis A.

If the blood test finds a different type of hepatitis A antibody, then you are immune to hepatitis A. You may be immune to hepatitis A because you had a past infection or received the vaccine.

How do doctors treat hepatitis A?

To treat hepatitis A symptoms, your doctor may recommend resting, drinking plenty of liquids, and consuming healthy foods and drinks. Your doctor may also suggest medicines to help relieve symptoms.

If you’re diagnosed with hepatitis A, talk with your doctor before taking any prescription or over-the-counter medicines, vitamins or other dietary supplements, or complementary or alternative medicines. Some of these could damage your liver. You should avoid alcohol until your doctor tells you that you have completely recovered from hepatitis A.

Most people recover from hepatitis A on their own within 6 months.⁶ See your doctor again if you continue to have symptoms after 6 months.

Can I prevent hepatitis A?

You can protect yourself from hepatitis A by getting the hepatitis A vaccine.

If you had hepatitis A in the past, you can’t get hepatitis A again. However, you can still get other types of viral hepatitis.

You can protect yourself from hepatitis A by getting the hepatitis A vaccine.

Hepatitis A vaccine

Health care professionals usually give the hepatitis A vaccine in two shots. The second shot is given at least 6 months after the first shot. You need to get both shots to be fully protected against the virus. A combined hepatitis A and hepatitis B vaccine is also available for adults.

Doctors recommend the hepatitis A vaccine for⁷

• all children between ages 12 months and 23 months
• older children who haven’t yet received the vaccine
• adults who are more likely to get hepatitis A, have chronic liver disease or HIV infection, are traveling to a country where hepatitis A is more common, or want to receive the vaccine

Reduce your chance of infection

If you haven’t been vaccinated against hepatitis A, you can reduce your chance of getting a hepatitis A infection by washing your hands. Wash your hands thoroughly with soap and water for at least 20 seconds

• after using the toilet
• after changing diapers
• before and after handling or preparing food

If you don’t have soap and water available, use a hand sanitizer that is at least 60% alcohol.

If you think you had contact with the hepatitis A virus, see your doctor right away. If taken soon after contact, a dose of the hepatitis A vaccine or a medicine called immune globulin (IG) may protect you from infection.

Your doctor may recommend getting the hepatitis A vaccine or IG if you

• live with or had sex or close contact with someone who has hepatitis A
• shared illegal drugs with someone who has hepatitis A
• ate food or drank water possibly containing the hepatitis A virus

Advice for international travelers

If you’re planning to travel internationally and you haven’t received the hepatitis A vaccine, ask your doctor if you should get the vaccine.

When traveling to countries where hepatitis A is common, choose safer food and drink options, such as bottled water instead of tap water. You can also use bottled water to brush your teeth, make ice cubes, and wash fruits and vegetables. Doctors may also recommend that some travelers take hepatitis A IG.

When traveling in a country where hepatitis A is common, drink bottled water.

How can I prevent spreading hepatitis A to others?

If you have hepatitis A, you can lower your chance of spreading the infection by washing your hands with soap and water after using the toilet. While you’re sick, avoid close contact with others. Don’t prepare food or serve food to others. Also, tell your doctor, dentist, and other health care professionals that you have hepatitis A.

You’re most contagious—able to spread the virus to others—during the 2 weeks before you have symptoms. You may be contagious for up to 3 weeks after you develop symptoms. Children are often contagious longer than adults.²

What should I eat and drink if I have hepatitis A?

If you have hepatitis A, choose healthy foods and drinks. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

Clinical Trials for Hepatitis A

NIDDK conducts and supports clinical trials in many diseases and conditions, including liver diseases. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.

What are clinical trials for hepatitis A?

Clinical trials—and other types of clinical studies—are part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.

Researchers are studying many aspects of hepatitis A, such as improving hepatitis A vaccination.

Find out if clinical studies are right for you.

Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.

What clinical studies for hepatitis A are looking for participants?

You can find clinical studies on hepatitis A at ClinicalTrials.gov. In addition to searching for federally funded studies you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health does not review these studies and cannot ensure they are safe for you. Always talk with your health care provider before you participate in a clinical study.

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