Hepatitis B is spread through contact with blood or other bodily fluids of infected people, as when people share unsterilized needles to inject illicit drugs.
Hepatitis B causes typical symptoms of viral hepatitis (including loss of appetite, a general feeling of illness, and jaundice) and may cause a severe form of hepatitis called fulminant hepatitis.
Doctors diagnose hepatitis B based on blood tests.
Vaccination against hepatitis B is recommended for all children and for adults likely to be exposed to the infection or to develop severe complications of the infection.
There is no specific treatment for acute hepatitis B.
Most people recover completely, but a few develop chronic hepatitis B.
If severe (fulminant) hepatitis develops, antiviral drugs can help, but the best hope of survival is liver transplantation.
(See also Overview of Hepatitis Overview of Hepatitis Hepatitis is inflammation of the liver. (See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.) Hepatitis is common throughout the world. Hepatitis can be Acute (short-lived) read more , Overview of Acute Viral Hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is inflammation of the liver, generally meaning inflammation caused by infection with one of the five hepatitis viruses. In most people, the inflammation begins suddenly... read more , and Hepatitis B, Chronic Hepatitis B, Acute Acute hepatitis B is inflammation of the liver that is caused by the hepatitis B virus and that lasts from a few weeks up to 6 months. Hepatitis B is spread through contact with blood or other... read more .)
The hepatitis B virus is the second most common cause of acute viral hepatitis. In the United States, over 3,000 cases of acute hepatitis B infection were reported in 2018—a decrease from the 25,000 annual cases reported before use of hepatitis B vaccine became widespread. However, many cases are not recognized or not reported. So the actual number of new infections may be much higher. It was estimated to be about 21,600 in 2018.
Occasionally, hepatitis D Hepatitis D Hepatitis D virus is infection of the liver that occurs only in people who have hepatitis B. Hepatitis D can be spread by contact with blood and other body fluids. Coinfection with hepatitis... read more infection coexists in people with acute hepatitis B.
Transmission of hepatitis B
Hepatitis B is less easily transmitted than hepatitis A. Transmission commonly occurs when needles are reused without being first sterilized—as when people share needles to inject drugs or when needles are reused to apply tattoos.
Transmission through blood transfusions is possible but is now rare in the United States because blood is screened.
Hepatitis B is also spread through contact with saliva, tears, breast milk, urine, vaginal fluid, and semen, but such spread is less common than blood-to-blood transmission.
Transmission may occur between sex partners, both heterosexual and homosexual. Also at increased risk are people living in close quarters (such as prisons and mental health institutions) because contact with another person's body fluid is more likely.
A pregnant woman infected with hepatitis B can transmit the virus to her baby during birth (see Hepatitis B Virus [HBV] Infection in Newborns Hepatitis B Virus (HBV) Infection in Newborns Hepatitis B virus infection causes inflammation of the liver. Newborns may become infected at birth or rarely after birth. Newborns who develop symptoms have jaundice, lethargy, and failure... read more ).
Anyone with hepatitis B, even people who do not have symptoms, can transmit the virus.
Whether insect bites can transmit this virus is not clear.
Many cases of hepatitis B have no known source.
Chronic hepatitis B
Overall, about 5% to 10% of people infected with the hepatitis B virus develop chronic hepatitis B Hepatitis B, Chronic Chronic hepatitis B is inflammation of the liver that is caused by the hepatitis B virus and that has lasted more than 6 months. Most people with chronic hepatitis B have no symptoms, but some... read more .
The younger the person is when acute hepatitis B occurs, the higher the risk of developing chronic hepatitis B:
Children aged 1 to 5 years: 25 to 50%
Adults: About 5%
If hepatitis B becomes chronic, severe scarring of the liver (cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more ) can develop, and liver cancer Primary Liver Cancers Primary liver cancers are cancers that originate in the liver. The most common is hepatocellular carcinoma (hepatoma). At first, liver cancer usually causes only vague symptoms (such as weight... read more can eventually develop.
Symptoms of Acute Hepatitis B
In general, hepatitis B is more serious than hepatitis A and is occasionally fatal, especially in older people. The infection can be mild or very severe (called fulminant hepatitis Symptoms ). When people with hepatitis B also have hepatitis D, symptoms are more severe.
Most people with hepatitis B have typical symptoms of viral hepatitis. These symptoms include
Loss of appetite
A general feeling of illness (malaise)
Nausea and vomiting
Joint pains and itchy red hives on the skin (wheals) are more likely in people with hepatitis B than with other hepatitis viruses.
Symptoms last from a few weeks up to 6 months.
If fulminant hepatitis develops, people can become very ill very quickly. Toxic substances normally removed by the liver build up in the blood and reach the brain, causing hepatic encephalopathy Hepatic Encephalopathy Hepatic encephalopathy is deterioration of brain function that occurs in people with severe liver disease because toxic substances normally removed by the liver build up in the blood and reach... read more . People may lapse into a coma within days to weeks. Fulminant hepatitis may be fatal without a liver transplant, especially in adults.
Diagnosis of Acute Hepatitis B
Doctors suspect hepatitis based on typical symptoms, such as jaundice.
Testing usually begins with blood tests to determine how well the liver is functioning and whether it is damaged (liver tests Liver Blood Tests Liver tests are blood tests that represent a noninvasive way to screen for the presence of liver disease (for example, hepatitis in donated blood) and to measure the severity and progress of... read more ). Liver tests involve measuring the levels of liver enzymes and other substances produced by the liver.
If tests detect liver abnormalities, other blood tests are done to check for hepatitis virus infection. These blood tests can identify parts of specific viruses (antigens), specific antibodies produced by the body to fight the virus, and sometimes genetic material (RNA or DNA) of viruses.
If hepatitis B virus is confirmed and is severe (fulminant), doctors also check for the hepatitis D virus, which is present in up to 50% of people with fulminant hepatitis B.
Prevention of Acute Hepatitis B
High-risk behavior, such as sharing needles to inject drugs and having multiple sex partners, should be avoided.
All blood donors are tested for hepatitis B to prevent the spread of hepatitis B virus through transfusions. Also, even though the chance of getting hepatitis from transfusions is remote, doctors use transfusions only when there is no alternative. These measures have dramatically decreased the risk of getting hepatitis from a blood transfusion.
In the United States, vaccination against hepatitis B Hepatitis B Vaccine The hepatitis B vaccine helps protect against hepatitis B and its complications ( chronic hepatitis, cirrhosis, and liver cancer). Generally, hepatitis B is more serious than hepatitis A and... read more is recommended for
All people aged 18 and younger (starting at birth—see figure Routine Vaccinations for Infants, Children, and Adolescents Routine Vaccinations for Infants, Children, and Adolescents )
Any adult who wishes protection from hepatitis B
All unvaccinated adults whose risk of getting hepatitis B is increased, including pregnant women
People with chronic liver disease
If family members and close contacts of people with chronic hepatitis B have not been vaccinated, they should be vaccinated with the hepatitis B vaccine.
If the level of hepatitis B virus (viral load) is high in pregnant women, they are often given antiviral drugs during the last trimester of pregnancy to prevent transmission of the virus from mother to child.
People who are not vaccinated and have been exposed to hepatitis B, including infants born to mothers with hepatitis B, are given hepatitis B immune globulin (by injection into a muscle) and the vaccine. This combination prevents chronic hepatitis B in 75%, or it makes the disease less severe. Hepatitis B immune globulin contains antibodies obtained from the blood of people who have high levels of antibodies to hepatitis. If a pregnant woman has high levels of the virus, the risk of transmission to the child may be decreased by treating the woman with tenofovir, an antiviral drug, during the third trimester.
If people come in contact with the blood of someone who has hepatitis B, they are given hepatitis B immune globulin by injection. If they have not been vaccinated against hepatitis B, they are also vaccinated. If they have been vaccinated, blood tests are done to determine whether they are still protected. If they are not, they are vaccinated.
Treatment of Acute Hepatitis B
For severe (fulminant) hepatitis, antiviral drugs and liver transplantation
There is no specific treatment for acute hepatitis B.
People with hepatitis B should not drink alcohol because it can damage the liver further. There is no need to avoid certain foods or limit activity.
Most people can safely return to work after jaundice resolves.
If itching occurs, cholestyramine, taken by mouth, may relieve the itching.
If fulminant hepatitis develops, an antiviral drug, usually entecavir or tenofovir, is used. These drugs are taken by mouth. They increase the chance of survival.
Liver transplantation Liver Transplantation Liver transplantation is the surgical removal of a healthy liver or sometimes a part of a liver from a living person and then its transfer into a person whose liver no longer functions. (See... read more is the most effective treatment for fulminant hepatitis B and is the best hope of survival, particularly for adults.
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Centers for Disease Control and Prevention: Hepatitis B: This web site provides links to an overview of hepatitis B (including definitions, statistics, transmission, and screening) and information about the hepatitis B vaccine, symptoms, diagnosis, and treatment, as well as links to information for health care practitioners. Accessed May 19, 2022.