Question: What is hepatitis B?
Answer: 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 invade 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 an infection that only lasts a short time, and then the virus goes away. Some people have symptoms, which can last several weeks. In some cases, symptoms last up to 6 months.1 If the virus doesn’t go away, chronic hepatitis B infection occurs.

Most healthy adults and children older than age 5 years who have hepatitis B get better and don’t develop a chronic hepatitis B infection.2

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. People who have a weak immune system, such as those with HIV, may also have greater chance of developing chronic hepatitis B.

Among people infected with hepatitis B, chronic infection develops in about3

90% of infants younger than age 1 year
25% to 50% of children between ages 1 and 5 years
5% of adults
Question: How common is hepatitis B?
Answer: Hepatitis B infection is less common in the United States than in some other parts of the world.

Hepatitis B worldwide

In some parts of Africa, Asia, the Middle East, Eastern Europe, and South America, 2% or more of the population have chronic hepatitis B infections. In some areas of sub-Saharan Africa and Asia, more than 8% of the population have chronic hepatitis B infections.3 In some of these areas, hepatitis B infection rates are now lower than they were in the past but are still higher than in the United States.

Hepatitis B in the United States

The hepatitis B vaccine has been available in the United States since the 1980s. In 1991, doctors began recommending that newborn babies and children receive the hepatitis B vaccine. With more people getting the vaccine, the number of acute hepatitis B infections each year went down 88.5% between 1982 and 2015.4

In 2022, 2,126 cases of acute hepatitis B were reported. However, many hepatitis B cases aren’t reported.5

Researchers estimate that less than 0.35% of the U.S. population—about 1.17 million people—have chronic hepatitis B infections. Of these, most were born outside the United States.6
Question: Who is more likely to get hepatitis B?
Answer: 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 they1

were born in a part of the world where hepatitis B is common
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 the number of people with hepatitis B is high

People are also more likely to have hepatitis B if they

have HIV
have lived with or had sex with someone who has hepatitis B
have had multiple sex partners or have a history ofsexually transmitted disease
are men who have sex with men
inject drugs
have contact with blood, needles, or body fluids at their job
havehepatitis C
have been onkidney dialysis
live or work in a jail or prison

In the United States, hepatitis B spreads among adults mainly through contact with infected blood through the skin. This contact most often occurs during injection drug use or through sexual contact.
Question: Should I be screened for hepatitis B?
Answer: 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. Screening tests can help doctors diagnose and treat hepatitis B, which can lower your chances of developing serious health problems.

Doctors recommend hepatitis B screening for7

all adults at least once in their life, particularly if they were born outside of the United States
pregnant women during each pregnancy
infants born to someone with hepatitis B
anyone who wants to be screened

Doctors also recommend ongoing screening for people who are more likely to get hepatitis B.
Question: What are the complications of hepatitis B?
Answer: Hepatitis B may lead to serious complications. Early diagnosis and treatment can help prevent complications.

Acute hepatitis B complications

In rare cases, acute hepatitis B can lead to acute liver failure, a condition in which the liver suddenly stops working properly. People with acute liver failure may need 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 partially 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 properly. Liver failure is also called end-stage liver disease. People with liver failure may need a liver transplant.
liver cancer. Your doctor may suggest blood tests and anultrasoundor 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 chronic hepatitis B or had hepatitis B in the past, 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

are taking medicines that reduce the activity of the immune system, such aschemotherapy to treat cancermedicines prescribed to treat conditions that involve the immune system, such asinflammatory bowel disease,rheumatoid arthritis, andpsoriasismedicines prescribed for people receiving anorgan transplantorbone marrow transplantcorticosteroids, if taken for more than a few weeks
chemotherapy to treat cancer
medicines prescribed to treat conditions that involve the immune system, such asinflammatory bowel disease,rheumatoid arthritis, andpsoriasis
medicines prescribed for people receiving anorgan transplantorbone marrow transplant
corticosteroids, if taken for more than a few weeks
are taking medicines for hepatitis C
have HIV infection and stop taking certain HIV medicines

Doctors may test for current or past hepatitis B infection in people at risk for reactivated hepatitis B. Doctors can give medicines to prevent and treat reactivated hepatitis B in people who are at risk.

Hepatitis D

If you have hepatitis B, you can also get hepatitis D. Hepatitis D can be acute or chronic. Hepatitis D can only infect people who also have hepatitis B.
Question: What are the symptoms of hepatitis B?
Answer: Many people infected with hepatitis B have no symptoms.

Some people with acute hepatitis B have symptoms 2 to 5 months after they encounter the virus.1 These symptoms may include

darkerurinecolor and lighterstoolcolor
fatigue, or feeling tired
fever
pain in joints orabdomen
loss of appetite,nausea, orvomiting
yellowish eyes and skin, calledjaundice

Infants and children younger than age 5 years typically don’t have symptoms of acute hepatitis B. Older children and adults are more likely to have symptoms.3

In contrast, most people with chronic hepatitis B have few symptoms until complications such as cirrhosis develop, which could be decades after they were infected. For this reason, hepatitis B screening is important, even if you don’t have symptoms. Some symptoms of cirrhosis include

fatigue, or feeling tired
itchy skin
weight loss
confusion or difficulty thinking
edema, or swelling of the ankles
ascites, or swelling of the abdomen
Question: What causes hepatitis B?
Answer: 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 needles or other materials used for injecting drugs 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 not kept sterile—free from all viruses and other microorganisms—and were used on an infected person
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 or sneezed on by an infected person
drinking unclean water or untreated water that hasn’t been boiled
eating food that is unclean or hasn’t been properly cooked
hugging an infected person
shaking hands or holding hands with an infected person
sharing spoons, forks, and other eating utensils with an infected person
sharing foods and drinks with an infected person
sitting next to an infected person

Mothers who have hepatitis B can safely breastfeed their babies if steps are taken shortly after birth to prevent spreading the infection. However, you should avoid breastfeeding if your nipples are cracked or bleeding.
Question: How do doctors diagnose hepatitis B?
Answer: 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, whether you have a family history of hepatitis B or liver cancer, and factors that can make you more likely to get hepatitis B. Your doctor may also ask about other factors that could damage your liver, such as drinking alcohol.

Physical exam

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

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

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 getting liver damage
whether the virus levels in your body are high or low
whether you need treatment

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

Additional tests

If you have chronic hepatitis B, your doctor may recommend getting tested regularly to check for signs of liver damage, to find out how much liver damage you have, or to rule out other causes of liver disease. Tests may include

blood tests.
elastography, a special test that measures the stiffness of the liver. An increase in liver stiffness may be a sign of fibrosis, or scarring.
ultrasoundor other imaging tests to check for cirrhosis.
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.
Question: How do doctors treat hepatitis B?
Answer: In most cases, doctors don’t treat hepatitis B unless it becomes chronic. However, not everyone with chronic hepatitis B needs treatment.

If blood tests show that hepatitis B could be causing liver damage, doctors may prescribe antiviral medicines. These medicines can lower the chances of getting liver damage and other problems.

Hepatitis B medicines may cause side effects, but they’re extremely rare. Talk with your doctor about the potential side effects of treatment. If you are taking hepatitis B antiviral medicines, don’t stop taking the medicines without first talking with your doctor.

Check with your doctor before taking any prescription or over-the-counter medicines. For safety reasons, talk with your doctor before using dietary supplements, such as vitamins or complementary or alternative medicines or medical practices. Some of these could lead to liver damage.
Question: How do doctors treat the complications of hepatitis B?
Answer: If chronic hepatitis B leads to cirrhosis, see a doctor who is an expert in liver diseases. Doctors can treat the health problems related to cirrhosis with medicines. You may also need minor medical procedures or surgery. If you have cirrhosis, you have a higher chance of developing 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. Antiviral medicines and a medicine called hepatitis B immune globulin (HBIG) can prevent hepatitis B infection in the new liver.
Question: How can I protect myself from hepatitis B infection?
Answer: You can protect yourself from hepatitis B by getting the hepatitis B vaccine. If you haven’t had the vaccine, you can take steps to reduce your chance of infection.

Hepatitis B vaccine

Doctors most often give the hepatitis B vaccine in three shots over 6 months. You must get all three shots to be fully protected. Some adults may be able to get the hepatitis B vaccine in two shots.

The hepatitis B vaccine has been available since the 1980s. In the United States, doctors recommend the vaccine for everyone age 59 and younger who hasn’t already been vaccinated, including infants and children. Doctors also recommend the vaccine for adults over age 60 who are more likely to be infected with hepatitis B, have chronic liver disease, or want to get vaccinated.8

Some hepatitis B vaccines are safe during pregnancy.

If you’re traveling to countries where hepatitis B is more common and you haven’t received the hepatitis B vaccine, talk with your doctor about getting the vaccine. Try to get all the shots—or as many as you can—before you go. Even one shot may give you some protection against the virus.

Reduce your chance of infection

You can reduce your chance of getting hepatitis B infection by

not sharing needles or other materials used to inject drugs
wearing gloves if you must 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’ve 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 HBIG to help prevent infection. You must get the vaccine dose and, if needed, HBIG shortly after encountering the virus, preferably within 24 hours.2
Question: How can I prevent spreading hepatitis B to others?
Answer: If you have hepatitis B, follow the steps above to avoid spreading the infection. Your sex partners should get a hepatitis B test. If they aren’t infected, they should get the hepatitis B vaccine. You can protect others 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 of spreading the infection to your baby. Your doctor will check your virus levels during pregnancy. If virus levels are high, your doctor may recommend treatment during pregnancy. Treatment can 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’s 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.

Mothers who have hepatitis B can safely breastfeed their babies. If a baby receives HBIG and starts receiving the hepatitis B vaccine shortly after birth, hepatitis B is unlikely to spread from mother to child through breastfeeding.
Question: What should I eat and drink if I have hepatitis B?
Answer: If you have hepatitis B, choose healthy foods and drinks. Obesity can increase the chance of developing nonalcoholic fatty liver disease, or NAFLD (also referred to as metabolic dysfunction-associated steatotic liver disease, or MASLD). 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 drinking alcohol because it can cause more liver damage.
Question: Clinical Trials for Hepatitis B
Answer: 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—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

the long-term effects of chronic hepatitis B
hepatitis B vaccination improvements
preventing reactivated or worsening hepatitis B in people receiving cancer treatments or other treatments that suppress the immune system
new drugs to cure hepatitis B

Find out if clinical studies are right for you.

Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.

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 ClinicalTrials.gov. 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 for you. Always talk with your health care provider before you participate in a clinical study.

What have we learned about hepatitis B from NIDDK-funded research?

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

Another example is the Liver Cirrhosis Network (LCN), funded by NIDDK, the National Cancer Institute, and the National Institute on Alcohol Abuse and Alcoholism. The network conducts research to better understand factors that increase the risk of developing cirrhosis problems. The LCN also studies treatments that may improve the health of people with cirrhosis.