Health Encyclopedia

Hepatitis B

Definition

Hepatitis B is irritation and swelling (inflammation) of the liver due to infection with the hepatitis B virus (HBV).

Other types of viral hepatitis include hepatitis A, hepatitis C, and hepatitis D.

Causes

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

Exposure may occur:

After a needlestick or sharps injury
If any blood or other body fluid touches your skin, eyes or mouth, or open sores or cuts

People who may be at risk for 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

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

Symptoms

After you first become infected with the HBV:

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 HBV. This is called chronic hepatitis B.

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

You can spread the HBV to other people, even if you have no symptoms.

Exams and Tests

A series of blood tests, called the hepatitis viral panel, is done for suspected hepatitis. It can help detect:

New infection
Older infection that is still active
Older infection that is no longer active

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

You may also have a test to measure the level of HBV in your blood (viral load). This lets your health care provider know how your treatment is working.

People at higher risk for hepatitis should be screened with a blood test. This may be needed even when they have no symptoms. Factors that lead to increased risk include:

The risk factors described above in the Causes section.
People from countries where a higher number of people have hepatitis B. These countries or areas include Japan, some Mediterranean countries, parts of Asia and the Middle East, West Africa, and South Sudan.

Treatment

Acute hepatitis, unless severe, needs no treatment. Liver and other body functions are watched using blood tests. You should get plenty of rest, drink plenty of fluids, and eat healthy foods.

Some people with chronic hepatitis may be treated with antiviral drugs. These medicines can decrease or remove hepatitis B from the blood. Examples include pills such as tenofovir and lamivudine or an injection called interferon. They also help to reduce the risk for cirrhosis and liver cancer.

It is not always clear which people with chronic hepatitis B should receive drug therapy and when it should be started. You are more likely to receive these medicines if:

Your liver function is quickly becoming worse.
You develop symptoms of long-term liver damage.
You have high levels of the HBV in your blood.
You are pregnant.

For these medicines to work best, you need to take them as instructed by your provider. Ask what side effects you can expect and what to do if you have them. Not everybody who takes these medicines responds well.

If you develop liver failure, you may be considered for a liver transplant. A liver transplant is the only cure in some cases of liver failure.

Other steps you can take:

Avoid alcohol.
Check with your provider before taking any over-the-counter medicines or herbal supplements. This includes medicines such as acetaminophen, aspirin, or ibuprofen.

Severe liver damage or cirrhosis can be caused by hepatitis B.

Support Groups

More information and support for people with HBV condition and their families can be found by joining a support group. Ask your provider about liver disease resources and support groups in your area.

Outlook (Prognosis)

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

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

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

When to Contact a Medical Professional

Contact your provider if:

You develop symptoms of hepatitis B.
Your hepatitis B symptoms do not go away in 2 to 3 weeks, or new symptoms develop.
You belong to a high-risk group for hepatitis B and have not had the HBV vaccine.

Prevention

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 3 shots in the series by age 6 to 18 months.
Children younger than age 19 years 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.

The hepatitis B vaccine or a hepatitis B 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.

References

Centers for Disease Control and Prevention website. Adult Immunization Schedule Recommendations by age for ages 19 years or older, United States, 2023. www.cdc.gov/vaccines/schedules/hcp/imz/adult.html. Reviewed April 23, 2023. Accessed July 11, 2023.

Centers for disease control and prevention website. Child and Adolescent Immunization Schedule Recommendations by age for ages 18 years or younger, United States, 2023. www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html. Reviewed April 23, 2023. Accessed July 11, 2023.

Pawlotsky J-M. Chronic viral and autoimmune hepatitis. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 135.

Tang LSY, Covert E, Wilson E, Kottilil S. Chronic hepatitis B infection: a review. JAMA. 2018;319(17):1802-1813 PMID: 29715359 pubmed.ncbi.nlm.nih.gov/29715359/.

Terrault NA, Lok ASF, McMahon BJ, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. Hepatology. 2018;67(4):1560-1599. PMID: 29405329 www.ncbi.nlm.nih.gov/pmc/articles/PMC5975958/.

Review Date:2/6/2022
Reviewed By:Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Internal review and update on 07/12/2023 by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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