Hepatitis B is a disease of the liver caused by a virus (specifically, the
hepatitis B virus). Most people who get hepatitis B can get rid of the virus on their own, but others can develop chronic (or life-long) hepatitis B.
The cause of hepatitis B is an infection with the hepatitis B virus. The hepatitis B virus is a DNA virus that belongs to the genus Orthohepadnavirus of the Hepadnaviridae family.
Acute Versus Chronic Hepatitis B
There are two types of hepatitis B -- acute (recently acquired) and chronic (life-long).
For most people with acute hepatitis B, symptoms gradually get better within a couple of months. These people with have no long-lasting liver damage and will recover completely.
For some people, the body is not able to completely get rid of the virus. These people end up having a long-term liver infection. This is called chronic hepatitis B. People with chronic hepatitis B can infect others and are at an increased risk of serious liver disease, including
cirrhosis and
liver cancer. In the United States, an estimated 1.25 million people are chronically infected with HBV.