Hepatitis A is a viral infection that causes inflammation of the liver. Hepatitis A is very contagious and transmitted through food or water containing the virus.

Hepatitis refers to inflammation of the liver caused by exposure to toxins, alcohol misuse, immune diseases, or infection. Viruses cause the majority of cases of hepatitis, including all cases of hepatitis A.

Hepatitis A is a form of the disease caused by the hepatitis A virus (HAV). This is an acute (short-term) type of hepatitis, which usually requires no treatment.

Approximately 1.5 million cases of hepatitis A occur around the world each year, with annual rates increasing in the United States. This highly contagious form of hepatitis is spread primarily through contaminated food or water. It generally isn’t serious and usually causes no long-term effects. A hepatitis A infection usually goes away on its own.

Children under the age of 6 typically show no symptoms when they contract the virus. Older children, teens, and adults usually develop mild symptoms, which can include:

Symptoms usually appear 14 to 28 days after you contract the virus.

People develop a hepatitis A infection after contracting HAV. This virus is typically transmitted by ingesting food or liquid contaminated with fecal matter that contains the virus. Once transmitted, the virus spreads through the bloodstream to the liver, where it causes inflammation and swelling.

In addition to transmission from eating food or drinking water containing HAV, the virus can also be spread by close personal contact with someone who already has it. HAV is contagious, and a person who has hepatitis A can easily pass the disease to others living in the same household.

You can contract hepatitis A by:

  • eating food prepared by someone with the hepatitis A virus
  • eating food handled by preparers who don’t follow strict hand-washing routines before touching food that you eat
  • eating sewage-contaminated raw shellfish
  • having sex with someone who has the hepatitis A virus
  • drinking polluted water
  • coming in contact with hepatitis A-infected fecal matter

If you contract the virus, you’ll be contagious 2 weeks before symptoms even appear. The contagious period ends about 1 week after symptoms appear.

The No. 1 way to avoid getting hepatitis A is by getting the hepatitis A vaccine. This vaccine is given in a series of two injections, 6 to 12 months apart.

If you’re traveling to a country where hepatitis A transmission is more common, get your vaccination at least 2 weeks before traveling. It usually takes 2 weeks after the first injection for your body to start building immunity to hepatitis A. If you’re not traveling for at least a year, it’s best to get both injections before leaving.

Check your destination on the Centers for Disease Control and Prevention (CDC) site to see if you should get a hepatitis A vaccination.

To limit your chance of contracting hepatitis A, you should also:

  • thoroughly wash your hands with soap and warm water before eating or drinking, and after using the restroom
  • drink bottled water rather than local water in developing countries, or in countries where there’s a high risk of contracting hepatitis A
  • dine at established, reputable restaurants, rather than from street vendors
  • avoid eating peeled or raw fruit and vegetables in an area with low sanitation or hygienic standards

Hepatitis A is usually spread from person to person, making it highly contagious. But certain factors can increase your risk of contracting it, including:

  • living in (or spending an extended time in) an area where hepatitis A is common, including most countries with low sanitation standards or a lack of safe water
  • injecting or using illegal drugs
  • living in the same household as someone who’s hepatitis A-positive
  • having sexual activity with someone who’s hepatitis A-positive (barrier methods don’t adequately prevent the spread of hepatitis A)
  • being HIV-positive
  • working with non-human primates

The World Health Organization (WHO) reports that more than 90 percent of children living in countries with low sanitation standards will have had a hepatitis A infection by age 10.

In past decades, people with clotting disorders like hemophilia were at higher risk of contracting hepatitis A via transfusion therapy, though these cases are extremely rare today.

Some people have only a few symptoms and no signs of jaundice. Without visible signs of jaundice, it’s hard to diagnose any form of hepatitis through a physical examination. When symptoms are minimal, hepatitis A can remain undiagnosed.

After you discuss your symptoms with your doctor, they may order a blood test to check for the presence of a viral or bacterial infection. A blood test will reveal the presence (or absence) of the hepatitis A virus.

Complications due to a lack of diagnosis are rare.

There’s no formal cure for hepatitis A. Because it’s a short-term viral infection that goes away on its own, treatment is typically focused on reducing your symptoms.

After a few weeks of rest, the symptoms of hepatitis A usually begin to improve. To ease your symptoms, you should:

  • avoid alcohol
  • maintain a balanced diet
  • drink plenty of water
  • limit the use of over-the-counter medications per your doctor’s suggestions

With rest, your body will most likely recover completely from hepatitis A in a matter of weeks or a few months. Usually, there are no negative long-term consequences of having the virus.

In extremely rare cases, hepatitis A can lead to acute liver failure. This complication is most common in older adults and people who already have chronic liver disease. If this occurs, you’ll be hospitalized. Even in cases of liver failure, a full recovery is likely. Very rarely is a liver transplant required.

After contracting hepatitis A, your body builds immunity to the disease. A healthy immune system will prevent the disease from developing if you’re exposed to the virus again.