Hepatitis B

In this section:

What is hepatitis B?

Hepatitis B is a viral infection that causes liver inflammation and damage. Inflammation is swelling that occurs when tissues of the body become injured or infected. Inflammation can damage organs.

Viruses NIH external link invade normal cells in your body. Many viruses cause infections that can spread from person to person. The hepatitis B virus spreads through contact with an infected person’s blood, semen, or other body fluids.

You can take steps to protect yourself from hepatitis B, including getting the hepatitis B vaccine. If you have hepatitis B, you can take steps to prevent spreading hepatitis B to others.

The hepatitis B virus can cause an acute or chronic infection.

Acute hepatitis B

Acute hepatitis B is a short-term infection. Some people have symptoms, which may last several weeks. In some cases, symptoms last up to 6 months. Sometimes the body is able to fight off the infection and the virus goes away. If the body isn’t able to fight off the virus, the virus does not go away, and chronic hepatitis B infection occurs.

Most healthy adults and children older than 5 years who have hepatitis B get better and do not develop a chronic hepatitis B infection.⁶

Chronic hepatitis B

Chronic hepatitis B is a long-lasting infection. Your chance of developing chronic hepatitis B is greater if you were infected with the virus as a young child. About 90 percent of infants infected with hepatitis B develop a chronic infection. About 25 to 50 percent of children infected between the ages of 1 and 5 years develop chronic infections. However, only about 5 percent of people first infected as adults develop chronic hepatitis B.⁶

How common is hepatitis B?

Hepatitis B worldwide

Hepatitis B infection is more common in some other parts of the world than it is in the United States. Though less than 0.5 percent of the U.S. population has hepatitis B, 2 percent or more of the population is infected in areas such as Africa, Asia, and parts of the Middle East, Eastern Europe, and South America.^7,8,9

Hepatitis B infection has been especially common in some parts of the world, such as sub-Saharan Africa and parts of Asia, where 8 percent or more of the population was infected.⁹ In some of these areas, Hepatitis B infection rates are now lower than they were, but infection rates are still higher in these areas than in the United States.^8,9

Hepatitis B in the United States

In the United States, about 862,000 people have chronic hepatitis B.⁶ Asian Americans and African Americans have higher rates of chronic hepatitis B than other U.S. racial and ethnic groups.¹⁰ Researchers estimate that about half of the people living with chronic hepatitis B in the United States are Asian Americans and Pacific Islanders External link.¹¹ Chronic hepatitis B is also more common among people born in other countries than among those born in the United States.⁷

The hepatitis B vaccine has been available since the 1980s and, in 1991, doctors began recommending that children in the United States receive the hepatitis B vaccine. The annual rate of acute hepatitis B infections went down 88.5 percent between 1982 and 2015.¹² In 2017, the annual number of hepatitis B infections rose in some states.¹³ Experts think the rise was related to increases in injection drug use. Injection drug use increases the risk of hepatitis B infection.

Who is more likely to get hepatitis B?

People are more likely to get hepatitis B if they are born to a mother who has hepatitis B. The virus can spread from mother to child during birth. For this reason, people are more likely to have hepatitis B if they

were born in a part of the world where 2 percent or more of the population has hepatitis B infection
were born in the United States, didn’t receive the hepatitis B vaccine as an infant, and have parents who were born in an area where 8 percent or more of the population had hepatitis B infection

People are also more likely to have hepatitis B if they

are infected with HIV NIH external link, because hepatitis B and HIV spread in similar ways
have lived with or had sex with someone who has hepatitis B
have had more than one sex partner in the last 6 months or have a history of sexually transmitted disease NIH external link
are men who have sex with men
are injection drug users
work in a profession, such as health care, in which they have contact with blood, needles, or body fluids at work
live or work in a care facility for people with developmental disabilities NIH external link
have diabetes
have hepatitis C
have lived in or travel often to parts of the world where hepatitis B is common External link
have been on kidney dialysis
live or work in a prison
had a blood transfusion NIH external link or organ transplant before the mid-1980s

In the United States, hepatitis B spreads among adults mainly through contact with infected blood through the skin, such as during injection drug use, and through sexual contact.¹²

Should I be screened for hepatitis B?

Screening is testing for a disease in people who have no symptoms. Doctors use blood tests to screen for hepatitis B. Many people who have hepatitis B don’t have symptoms and don’t know they are infected with hepatitis B. Screening tests can help doctors diagnose and treat hepatitis B, which can lower your chances of developing serious health problems.

Your doctor may recommend screening for hepatitis B if you^9,14

are pregnant
were born in an area of the world where 2 percent or more of the population has hepatitis B infection, which includes Africa, Asia, and parts of the Middle East, Eastern Europe, and South America
didn’t receive the hepatitis B vaccine as an infant and have parents who were born in an area where 8 percent or more of the population had hepatitis B infection, which includes sub-Saharan Africa and parts of Asia
are HIV-positive
have injected drugs
are a man who has sex with men
have lived with or had sex with a person who has hepatitis B
have an increased chance of infection due to other factors

Doctor talking with a patient. — Your doctor may recommend screening for hepatitis B if you have an increased chance of infection.

What are the complications of hepatitis B?

Hepatitis B may lead to serious complications. Early diagnosis and treatment can lower your chances of getting complications.

Acute hepatitis B complications

In rare cases, acute hepatitis B can lead to acute liver failure, a condition in which the liver fails suddenly. People with acute liver failure may require a liver transplant.

Chronic hepatitis B complications

Chronic hepatitis B can lead to

cirrhosis, a condition in which scar tissue replaces healthy liver tissue and prevents your liver from working normally. Scar tissue also partly blocks the flow of blood through the liver. As cirrhosis gets worse, the liver begins to fail.
liver failure, in which your liver is badly damaged and stops working. Liver failure is also called end-stage liver disease. People with liver failure may require a liver transplant.
liver cancer NIH external link. Your doctor may suggest blood tests and an ultrasound or another type of imaging test to check for liver cancer. Finding cancer at an early stage improves the chance of curing the cancer.

Reactivated hepatitis B

In people who have ever had hepatitis B, the virus may become active again, or reactivated, later in life. When hepatitis B is reactivated, it may start to damage the liver and cause symptoms. Reactivated hepatitis B can lead to acute liver failure.

People at risk for reactivated hepatitis B include those who

take medicines that reduce the activity of the immune system, such as
- chemotherapy to treat cancer NIH external link
- medicines prescribed to treat conditions that involve the immune system, such as inflammatory bowel disease, rheumatoid arthritis NIH external link, and psoriasis NIH external link
- medicines prescribed for people receiving an organ transplant NIH external link or bone marrow transplant NIH external link
- corticosteroids NIH external link, if taken for more than a few weeks
take hepatitis C medicines
have HIV infection

Doctors may test for current or past hepatitis B infection in people at risk for reactivated hepatitis B.

What are the symptoms of hepatitis B?

Many people infected with hepatitis B have no symptoms.

Some people with acute hepatitis B have symptoms 2 to 5 months after they come in contact with the virus.⁶ These symptoms may include

dark yellow urine
feeling tired
fever
gray- or clay-colored stools
joint pain
loss of appetite
nausea
pain in the abdomen
vomiting
yellowish eyes and skin, called jaundice

Infants and children younger than age 5 typically don’t have symptoms of acute hepatitis B. Older children and adults are more likely to have symptoms.⁶

If you have chronic hepatitis B, you may not have symptoms until complications develop, which could be decades after you were infected. For this reason, hepatitis B screening is important, even if you have no symptoms.

What causes hepatitis B?

The hepatitis B virus causes hepatitis B. The hepatitis B virus spreads through contact with an infected person’s blood, semen, or other body fluids. Contact can occur by

being born to a mother with hepatitis B
having unprotected sex with an infected person
sharing drug needles or other drug materials with an infected person
getting an accidental stick with a needle that was used on an infected person
being tattooed or pierced with tools that were used on an infected person and weren’t properly sterilized, or cleaned in a way that destroys all viruses and other microbes
having contact with the blood or open sores of an infected person
using an infected person’s razor, toothbrush, or nail clippers

You can’t get hepatitis B from

being coughed on or sneezed on by an infected person
drinking unclean water or untreated water that has not been boiled
eating food that is unclean or has not been properly cooked
hugging an infected person
shaking hands or holding hands with an infected person
sharing spoons, forks, and other eating utensils
sitting next to an infected person

Mothers who have hepatitis B can safely breastfeed their babies. If a baby receives hepatitis B immune globulin (HBIG) and starts receiving the hepatitis B vaccine to prevent hepatitis B infection shortly after birth, hepatitis B is unlikely to spread from mother to child through breastfeeding.¹⁵

How do doctors diagnose hepatitis B?

Doctors diagnose hepatitis B based on your medical and family history, a physical exam, and blood tests. If you have hepatitis B, your doctor may perform additional tests to check your liver.

Medical and family history

Your doctor will ask about your symptoms and about factors that may make you more likely to get hepatitis B. Your doctor may ask whether you have a family history of hepatitis B or liver cancer. Your doctor may also ask about other factors that could damage your liver, such as drinking alcohol NIH external link.

Physical exam

During a physical exam, your doctor will check for signs of liver damage such as

changes in skin color
swelling in your lower legs, feet, or ankles
tenderness or swelling in your abdomen

What tests do doctors use to diagnose hepatitis B?

Doctors use blood tests to diagnose hepatitis B. Your doctor may order additional tests to check for liver damage, find out how much liver damage you have, or rule out other causes of liver disease.

Blood tests

Your doctor may order one or more blood tests to diagnose hepatitis B. A health care professional will take a blood sample from you and send the sample to a lab.

Certain blood tests can show whether you are infected with hepatitis B. If you are infected, your doctor may use other blood tests to find out

whether the infection is acute or chronic
whether you have an increased chance of liver damage
whether the virus levels in your body are high or low
whether you need treatment

If you have chronic hepatitis B, your doctor will recommend testing your blood regularly because chronic hepatitis B can change over time. Even if the infection is not damaging your liver when you are first diagnosed, it may damage your liver in the future. Your doctor will use regular blood tests to check for signs of liver damage, find out if you need treatment, or see how you are responding to treatment.

Blood tests can also show whether you are immune to hepatitis B, meaning you can’t get hepatitis B. You may be immune if you got a vaccine or if you had an acute hepatitis B infection in the past and your body fought off the infection.

Health care professional taking a blood sample from the arm of a patient. — Your doctor may order one or more blood tests to diagnose hepatitis B.

Additional tests

If you’ve had chronic hepatitis B a long time, you could have liver damage. Your doctor may recommend additional tests to find out whether you have liver damage, how much liver damage you have, or to rule out other causes of liver disease. These tests may include

blood tests
transient elastography, a special ultrasound of your liver
liver biopsy, in which a doctor uses a needle to take a small piece of tissue from your liver

Doctors typically use liver biopsy only if other tests don’t provide enough information about a person’s liver damage or disease. Talk with your doctor about which tests are best for you.

How do doctors treat hepatitis B?

Doctors typically don’t treat hepatitis B unless it becomes chronic. Doctors may treat chronic hepatitis B with antiviral medicines that attack the virus.

Not everyone with chronic hepatitis B needs treatment. If blood tests show that hepatitis B could be damaging a person’s liver, a doctor may prescribe antiviral medicines to lower the chances of liver damage and complications.

Medicines that you take by mouth include

entecavir NIH external link (Baraclude)
tenofovir alafenamide NIH external link (Vemlidy)
tenofovir disoproxil fumarate NIH external link (Viread)

A medicine that doctors can give as a shot is peginterferon alfa-2a NIH external link (Pegasys).

The length of treatment varies. Hepatitis B medicines may cause side effects. Talk with your doctor about the side effects of treatment. Tell your doctor before taking any other prescription or over-the-counter medicines.

For safety reasons, you also should talk with your doctor before using dietary supplements NIH external link, such as vitamins, or any complementary or alternative medicines NIH external link or medical practices.

How do doctors treat the complications of hepatitis B?

If chronic hepatitis B leads to cirrhosis, you should see a doctor who specializes in liver diseases. Doctors can treat the health problems related to cirrhosis with medicines, minor medical procedures, and surgery. If you have cirrhosis, you have an increased chance of liver cancer. Your doctor may order blood tests and an ultrasound or another type of imaging test to check for liver cancer.

If chronic hepatitis B leads to liver failure or liver cancer, you may need a liver transplant.

How can I protect myself from hepatitis B infection?

You can protect yourself from hepatitis B by getting the hepatitis B vaccine External link. If you have not had the vaccine, you can take steps to reduce your chance of infection.

Hepatitis B vaccine

The hepatitis B vaccine has been available since the 1980s and should be given to newborns, children, and teens in the United States. Adults who are more likely to be infected with hepatitis B or who have chronic liver disease should also get the vaccine. The hepatitis B vaccine is safe for pregnant women.

Doctors most often give the hepatitis B vaccine in three shots over 6 months. You must get all three shots to be fully protected. In some cases, doctors may recommend a different number or timing of vaccine shots.

If you are traveling to countries where hepatitis B is common External link and you haven’t received the hepatitis B vaccine, talk with your doctor and try to get all the shots before you go. If you don’t have time to get all the shots before you travel, get as many as you can. Even one shot may give you some protection against the virus.

Doctor giving a vaccine shot to a small child. — The hepatitis B vaccine should be given to newborns, children, and teens in the United States.

Reduce your chance of infection

You can reduce your chance of hepatitis B infection by

not sharing drug needles or other drug materials
wearing gloves if you have to touch another person’s blood or open sores
making sure your tattoo artist or body piercer uses sterile tools
not sharing personal items, such as toothbrushes, razors, or nail clippers
using a latex or polyurethane condom during sex

Prevent infection after contact with the virus

If you think you have been in contact with the hepatitis B virus, see your doctor right away. Doctors typically recommend a dose of the hepatitis B vaccine to prevent infection. In some cases, doctors may also recommend a medicine called hepatitis B immune globulin (HBIG) to help prevent infection. You must get the vaccine dose and, if needed, HBIG shortly after coming into contact with the virus, preferably within 24 hours.

How can I prevent spreading hepatitis B to others?

If you have hepatitis B, follow the steps above to avoid spreading the infection. Your sex partners should get a hepatitis B test and, if they aren’t infected, get the hepatitis B vaccine. You can protect others from getting infected by telling your doctor, dentist, and other health care professionals that you have hepatitis B. Don’t donate blood or blood products, semen, organs, or tissue.

Prevent hepatitis B infections in newborns

If you are pregnant and have hepatitis B, talk with your doctor about lowering the risk that the infection will spread to your baby. Your doctor will check your virus levels during pregnancy. If virus levels are high, your doctor may recommend treatment during pregnancy to lower virus levels and reduce the chance that hepatitis B will spread to your baby. Your doctor may refer you to a liver specialist to find out if you need hepatitis B treatment and to check for liver damage.

When it is time to give birth, tell the doctor and staff who deliver your baby that you have hepatitis B. A health care professional should give your baby the hepatitis B vaccine and HBIG right after birth. The vaccine and HBIG will greatly reduce the chance of your baby getting the infection.

A newborn baby. — If you are pregnant and have hepatitis B, your baby should receive the hepatitis B vaccine and HBIG right after birth.

Eating, diet, and nutrition for hepatitis B

If you have hepatitis B, you should eat a balanced, healthy diet. Obesity can increase the chance of nonalcoholic fatty liver disease (NAFLD), and NAFLD can increase liver damage in people who have hepatitis B. Talk with your doctor about healthy eating and maintaining a healthy weight.

You should also avoid alcohol because it can cause more liver damage.

Clinical Trials for Hepatitis B

The NIDDK conducts and supports clinical trials in many diseases and conditions, including liver diseases. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.

What are clinical trials for hepatitis B?

Clinical trials—and other types of clinical studies NIH external link—are part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.

Researchers are studying many aspects of hepatitis B, such as

progression of hepatitis B and long-term outcomes
new treatments for hepatitis B
prevention of reactivated or worsening hepatitis B in people receiving cancer treatment

Find out if clinical studies are right for you NIH external link.

What clinical studies for hepatitis B are looking for participants?

You can view a filtered list of clinical studies on hepatitis B that are federally funded, open, and recruiting at www.ClinicalTrials.gov NIH external link. You can expand or narrow the list to include clinical studies from industry, universities, and individuals; however, the NIH does not review these studies and cannot ensure they are safe. Always talk with your health care provider before you participate in a clinical study.

How is NIDDK- and NIH-funded research advancing the understanding of hepatitis B?

The NIDDK and the NIH have supported many research projects to learn more about hepatitis B, including the NIDDK’s Hepatitis B Research Network (HBRN) External link. The HBRN, a network of 28 clinical sites throughout the United States and Canada, studies how hepatitis B affects children and adults and explores new approaches to diagnosis and treatment.