Hepatitis B is a viral infection that causes inflammation of the liver. Test results can identify present hepatitis B infection, past exposure to HBV, or immunity to the virus.

HBV is spread through contact with body fluids. Most frequently, it is spread from blood-to-blood contact, but it may be transmitted through other body fluids. Common forms of exposure to HBV vary based on geographical area but often occur during childbirth and infancy, when sharing needles for intravenous drug use, or during unprotected sex.

A hepatitis B infection can be acute or chronic. Acute hepatitis B is a short-lived infection. You can usually recover completely from acute hepatitis B without treatment within a few weeks to six months.

Around 5 to 10% of patients with acute hepatitis B progress to having chronic hepatitis B, a long-term infection lasting six months or longer. If you have chronic hepatitis B, you are at an increased risk of developing complications, including