What is hepatitis B?

Hepatitis B is an infection of the liver which is caused by the hepatitis B virus. Some people may experience acute hepatitis B while others may experience chronic hepatitis B. About 12 million Americans have been infected with hepatitis B. It is estimated that more than one million people are chronically infected, and up to 40,000 new people will become infected each year.


Hepatitis B may be either be acute or chronic. Acute hepatitis B lasts less than six months. The immune system is usually able to fight acute hepatitis B on its own. It usually takes a couple of months to be free of acute hepatitis B. Most people who develop hepatitis B as adults have an acute infection. However, it can sometimes lead to chronic infection. Chronic hepatitis B lasts six months or longer. This lasts longer because the immune system was unable to fight the initial acute infection. People who develop chronic hepatitis B infection may have it for the rest of their lives. In this case, it may lead serious conditions such as cirrhosis and liver cancer.

The signs and symptoms of hepatitis B may be moderate to severe. They usually show up around one to four months after being infected. Signs and symptoms of hepatitis B may include abdominal pain, dark urine, fever, joint pain, loss of appetite, nausea and vomiting, weakness, fatigue, and yellowing of your skin and the whites of your eyes (aka jaundice).

The hepatitis B virus is transmitted via blood, semen or other body fluids. The most common ways the virus is transmitted include sexual contact (having unprotected sex with an infected partner), sharing needles with infected people, accidental needle sticks while working in a healthcare system, and during childbirth in which the mother is infected with the hepatitis B virus. 

There are a number of risk factors that may increase your risk of developing hepatitis B. Your risk of hepatitis B increases if you have unprotected sex with multiple sex partners or with someone who's infected with HBV, share needles during intravenous drug use, are a man who has sex with other men, live with someone who has a chronic HBV infection, are an infant born to an infected mother, have a job that exposes you to human blood, or travel to regions with high infection rates of HBV, such as Africa, Central and Southeast Asia, and Eastern Europe.