Hepatitis B is a viral infection that causes liver inflammation and damage. The hepatitis B virus spreads through contact with an infected person's blood, semen, or other body fluids. In the United States, sexual contact is the most common way that hepatitis B spreads among adults. It can cause acute or chronic infection.
With acute, or short-term, hepatitis B infection, symptoms may last several weeks up to six months. Most healthy adults who have hepatitis B have an acute infection that their body is able to fight off without treatment.
The symptoms of acute hepatitis B may appear two to five months after a person comes in contact with the virus. These symptoms can include:
- Dark yellow urine
- Pale or clay-colored stool
- Joint pain
- Loss of appetite
- Abdominal pain
- Jaundice, or yellowing of the eyes and skin
Chronic, or long-lasting, hepatitis B occurs when the body isn't able to fight off the virus. Chances of developing a chronic hepatitis B infection are greater for those infected as children.
Chronic hepatitis B may produce symptoms similar to acute hepatitis B when a person is initially exposed to the virus. The symptoms may not be as severe, and the person may not realize they've been infected until complications develop, sometimes years later. Those complications can include fibrosis, cirrhosis, liver failure, and liver cancer.
Fibrosis is scarring of the liver, which causes it to slowly deteriorate, ultimately leading to end-stage fibrosis or cirrhosis. People who develop cirrhosis are at risk for chronic liver failure, also called end-stage liver disease. At this point, the liver can no longer perform important functions or replace damaged cells. However, cirrhosis is not the same as liver failure.
A vaccine for hepatitis B has been available since the 1980s, and should be given to newborns, children, and adults who have not yet been vaccinated. The vaccine is most often given in three shots over six months. All three shots are necessary to be fully protected.