What is the difference between hepatitis A vs. hepatitis B?

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The hepatitis A virus causes an acute liver infection, which people refer to as hepatitis A. The virus is highly contagious and can spread through oral contact with fecal matter, which people can encounter in foods or water or through close physical contact with someone who has the virus.

Some people with hepatitis A will not develop any signs or symptoms. Adults are the most likely to develop symptoms, which can last for less than 2 months to more than 6 months.

Learn more about hepatitis A.

Hepatitis B is another viral infection that affects the liver. The condition may be acute or chronic. Chronic hepatitis B affects 880,000 to 1.89 million people in the United States.

Hepatitis B has several similar symptoms to hepatitis A. Most adults with compromised immune systems and children under 5 years of age will show no symptoms. An estimated 30–50% of otherwise healthy adults will show signs and symptoms of hepatitis B.

Learn more about hepatitis B.

Hepatitis A and hepatitis B have some similarities.

Both conditions directly affect the liver. According to the Centers for Disease Control and Prevention (CDC), hepatitis A and hepatitis B may not cause any symptoms. When either condition does cause symptoms, a person may notice the following:

• fever
• fatigue
• loss of appetite
• nausea
• vomiting
• abdominal pain
• dark urine
• light-colored stools
• joint pain
• jaundice

Vaccines are available for hepatitis A and hepatitis B. The CDC recommends that all infants get both vaccinations, but advice varies on when older children and adults should get vaccinated.

Learn more about the hepatitis B vaccine.

Though hepatitis A and hepatitis B both affect the liver, they have several differences.

How they spread

Hepatitis B spreads through contact with bodily fluids such as vaginal secretions, blood, semen, and saliva. It can spread through sexual contact, sharing needles or other instruments that can puncture the skin, or other activities that spread saliva or other fluids between people.

Learn more about hepatitis B carriers and transmission.

Hepatitis A typically spreads through the fecal-oral route, such as when a person consumes food or water containing the virus or has sexual contact with someone who has the virus.

In the United States, hepatitis A often results from contact with food or feces containing the virus. For example, transmission can occur if people do not wash their hands after using the toilet and before preparing food.

Reinfection

Once a person has had a hepatitis A infection and recovered, they cannot contract it again. This is because people can develop antibodies to the hepatitis A virus.

The hepatitis B virus, however, can reactivate and become chronic in people who have previously recovered from it. Reactivation can result from a sudden rise or reappearance of hepatitis B DNA in a person’s body.

Learn more about hepatitis B and immunity.

Length of infection

Hepatitis B can be a chronic condition that lasts for the rest of a person’s life. People often do not know they have the infection.

Learn more about the hepatitis B incubation period.

Hepatitis A is an acute infection that lasts a few weeks to a few months. Once a person recovers, they cannot contract it again.

Cancer risk

Hepatitis B can increase a person’s chances of developing liver cancer and is a leading cause of liver cancer.

People who have had hepatitis A do not have an increased risk of liver cancer.

Risk of liver damage

According to the CDC, 15–25% of people with chronic hepatitis B develop liver damage, liver failure, or liver cancer.

However, hepatitis A does not cause chronic liver damage in most people. In rare cases, severe hepatitis A can lead to liver failure, which may result in the need for a liver transplant.

Hepatitis A typically spreads through a fecal-oral route, often via food that contains the virus. A person can help prevent infection by:

• thoroughly washing their hands before and after using the toilet, before preparing food, and after changing diapers
• sanitizing surfaces that may have had contact with the virus
• getting vaccinated, particularly before international travel
• heating foods to 185°F (85°C) or higher for at least 1 minute

Hepatitis B can spread through sexual contact and sharing instruments that puncture the skin or come in contact with bodily fluids. Some ways to reduce exposure risk include:

• using barrier methods during sex
• avoiding recreational drug use involving needles
• not sharing razors, toothbrushes, or other objects that come in contact with bodily fluids
• getting vaccinated
• wearing gloves when cleaning up blood that contains the virus

Learn more about viral hepatitis and prevention.

Here are some frequently asked questions about hepatitis A and hepatitis B.

Is hepatitis A worse than hepatitis B?

Both hepatitis A and hepatitis B affect a person’s liver. Hepatitis A is an acute infection. In rare cases, a person may need hospitalization to treat dehydration.

A person may feel worse during a hepatitis A infection but will recover from it. With hepatitis B, they may develop a chronic infection that can cause liver damage and liver cancer.

Do you need both a hepatitis A and hepatitis B vaccine?

Hepatitis A and hepatitis B are different viruses that require different vaccines. In the United States, the CDC recommends all infants and members of other high risk groups get both vaccinations.

While hepatitis A and hepatitis B both affect the liver and have similar symptoms, they are different viruses. They differ in transmission methods, potential complications, and outlook.

Hepatitis A is an acute infection that can spread through contact with food or feces that contains the virus. Hepatitis B spreads through contact with blood, semen, or other bodily fluids.

Hepatitis B can turn into a lifelong condition, but a person will typically fully recover from a hepatitis A infection.

A person can prevent both infections through vaccination and by taking precautions, such as using barrier methods during sex and thoroughly washing their hands after using the bathroom.