Hepatitis B infection is caused by the hepatitis B virus (HBV).You can catch hepatitis B through contact with the blood or body fluids (such as semen, vaginal fluids, and saliva) of a person who has the virus.

Exposure may occur:

• After a needle stick or sharps injury
• If any blood or other body fluid touches your skin, eyes or mouth

People who may be at risk of hepatitis B are those who:

• Have unprotected sex with an infected partner
• Receive blood transfusions (not common in the United States)
• Have contact with blood at work (such as health care workers)
• Have been on long-term kidney dialysis
• Get a tattoo or acupuncture with unclean needles
• Share needles during drug use
• Share personal items (such as toothbrush, razor, and nail clippers) with a person who has the virus
• Were born to a hepatitis-B infected mother

After you first become infected with the hepatitis B virus:

• You may have no symptoms
• You may feel sick for a period of days or weeks
• You may become very ill very quickly (called fulminant hepatitis)

Symptoms of hepatitis B may not appear for up to 6 months after the time of infection. Early symptoms include:

• Appetite loss
• Fatigue
• Low fever
• Muscle and joint aches
• Nausea and vomiting
• Yellow skin and dark urine

Symptoms will go away in a few weeks to months if your body is able to fight off the infection. Some people never get rid of the hepatitis B virus. This is called chronic hepatitis B.

People with chronic hepatitis may not have symptoms and not know they are infected. Over tiem, they may develop symptoms of liver damage and cirrhosis of the liver.

You can spread the hepatitis B virus to other people even if you have no symptoms.

A series of blood tests called the hepatitis viral panel is done to help diagnose the condition.

The following tests are done to look for liver damage if you have chronic hepatitis B:

• Albumin level
• Liver function tests
• Prothrombin time

You will also have a test to measure the level of HPV in your blood (viral load). This lets your doctors know how your treatment is working.

Some people benefit from attending a liver disease support group.

The acute illness usually goes away after 2 - 3 weeks. The liver usually returns to normal within 4 - 6 months in most people.

Almost all newborns and about half of children who get hepatitis B develop the chronic condition. Very few adults who get the virus develop chronic hepatitis B.

About 1 in 100 people who get hepatitis B dies from the condition.

There is a much higher rate of liver cancer in people who have chronic hepatitis B.

Children and people at high risk for hepatitis B should get the hepatitis B vaccine.

• Babies should get a first dose of the hepatitis B vaccine at birth. They should have all three shots in the series by age 6 months.
• Children younger than age 19 who have not had the vaccine should get "catch-up" doses.
• Health care workers and those who live with someone who has hepatitis B should get the vaccine.
• Infants born to mothers who have acute hepatitis B or have had the infection in the past should get a special hepatitis B vaccine within 12 hours of birth.

All blood used for blood transfusions is screened, so the chance of getting the virus in this way is very small.

The hepatitis B vaccine or a hepatitis immune globulin (HBIG) shot may help prevent infection if you receive it within 24 hours of contact with the virus.

Measures to avoid contact with blood and body fluids can help prevent the spread of hepatitis B from person to person.

Dienstag JL. Hepatitis B virus infection. N Engl J Med. 2008;359:1486-1500.

Perrillo R. Hepatitis B and D. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier;2010:chap 78.

Sorrell MF, Belongia EA, Costa J, Gareen IF, Grem JL, Inadomi JM, et al. National Institutes of Health Consensus Development Conference Statement: Management of hepatitis B. Ann Intern Med. 2009;150:104-10.