• Consumer Health: Understanding hepatitis

human body anatomy with the liver highlighted

World Hepatitis Day will be observed Thursday, July 28, which makes this a good time to learn more about three types of hepatitis.

Hepatitis is inflammation of the liver. The five main strains of the hepatitis virus are referred to as types A, B, C, D and E. While they all cause liver disease, they differ in geographic prevalence, modes of transmission, severity of illness and prevention methods.

In the U.S., the most common types of hepatitis are:

Hepatitis A

Hepatitis A is highly contagious, spreading through contact with contaminated food or water, or from close contact with an infected person or object. Unlike other types of viral hepatitis, hepatitis A does not cause long-term liver damage, and it doesn't become chronic.

In rare cases, hepatitis A can cause a sudden loss of liver function, especially in older adults or people with chronic liver diseases. Acute liver failure requires a stay in the hospital for monitoring and treatment. Some people with acute liver failure may need a liver transplant.

Mild cases of hepatitis A don't require treatment, and most people who are infected recover completely with no permanent liver damage. Practicing good hygiene, including frequent hand-washing, is one of the best ways to protect against hepatitis A.

Vaccines are available for people most at risk.

Hepatitis B

Hepatitis B is passed from person to person through blood, semen or other bodily fluids. It does not spread by sneezing or coughing.

For some people, hepatitis B infection becomes chronic, which increases their risk of developing liver failureliver cancer or cirrhosis. The younger people are when they get hepatitis B, particularly newborns or children younger than 5, the higher the risk of the infection becoming chronic.

Chronic infection may go undetected for decades until a person becomes seriously ill from liver disease. A vaccine can prevent hepatitis B, but there's no cure if you have the condition.

Hepatitis B is a common reason for liver transplants in the U.S.

Hepatitis C

Hepatitis C is transmitted primarily by infected blood, and it also is a common reason for liver transplants in the U.S. Hepatitis C usually can be cured with oral medications taken every day for two to six months. But many people don't know they're infected because they have no symptoms, which can take decades to appear.

Hepatitis C infection that continues over many years can cause significant complications, including cirrhosisliver cancer and liver failure. The Centers for Disease Control and Prevention recommends that all adults be screened for hepatitis C, even those without symptoms or known liver disease. The largest group at risk includes everyone born between 1945 and 1965 — a population five times more likely to be infected than those born in other years.

Connect with others talking about hepatitis and liver failure in the Transplants support group on Mayo Clinic Connect, an online patient community moderated by Mayo Clinic.

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