HEPATITIS B DIAGNOSIS

Hepatitis B is diagnosed by detecting one of the viral antigens--called hepatitis B surface antigen (HBsAg)--in the blood. Later in the acute disease, HBsAg may no longer be present, in which case a test for antibodies to a different antigen--hepatitis B core antigen--is used. If HBsAg can be detected in the blood for longer than six months, chronic hepatitis B is diagnosed. A number of tests can be done to learn how well, or poorly, the liver is working. They include blood clotting tests and tests for enzymes which are found in abnormally high amounts when any form of hepatitis is present.