Due to current HHS and NIH restructuring, the information provided on niddk.nih.gov is not being updated. Please refer to nih.gov.

U.S. flag

An official website of the United States government

NIH: National Institute of Diabetes and Digestive and Kidney Diseases NIH: National Institute of Diabetes and Digestive and Kidney Diseases 75 years: 1950-2025 75 years: 1950-2025
  1. Home
  2. Health Information
  3. Liver Disease
  4. Viral Hepatitis
  5. View All Content

Hepatitis (Viral)

Return to Overview Page

What Is Viral Hepatitis?

Viral hepatitis is an 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. Researchers have discovered several different viruses that cause hepatitis, including hepatitis A, B, C, D, and E.

A liver infected with viruses on a human torso. Viral hepatitis is an infection that causes liver inflammation and damage.

Hepatitis A and hepatitis E typically spread when a person consumes food or water that has been contaminated by an infected person’s stool. People may also get certain forms of hepatitis E by eating undercooked pork or wild animals, or if they consume water that has come in contact with stool from an infected animal.

Hepatitis B, hepatitis C, and hepatitis D spread through contact with an infected person’s blood. Hepatitis B and D may also spread through contact with other body fluids. This contact can occur in many ways, including by sharing drug needles or having unprotected sex.

The hepatitis A and E viruses typically cause only acute infections. An acute infection lasts a short time, and then the virus goes away.

The hepatitis B, C, and D viruses can cause acute and chronic, or long-lasting, infections. Chronic hepatitis occurs when the hepatitis virus stays in your body and doesn’t go away. Chronic hepatitis can lead to problems such as cirrhosis, liver failure, and liver cancer. Early diagnosis and treatment of chronic hepatitis can prevent or lower your chances of developing these problems.

Not all hepatitis is caused by a virus. Other causes include autoimmune hepatitis, a chronic disease in which your body’s immune system attacks the liver. Some medicines and herbal supplements also can cause hepatitis.

Hepatitis A

In this section:

What is hepatitis A?

Hepatitis A is a viral infection that causes short-term liver inflammation and damage. Inflammation is swelling that occurs when tissues of the body become injured or infected.

Viruses invade cells in your body. Many viruses cause infections that can spread from person to person. The hepatitis A virus typically spreads through consuming food or water that has been contaminated by stool from a person infected with hepatitis A.

Hepatitis A is an acute infection, which means it lasts only a short time. People usually get better without treatment after a few weeks. In rare cases, hepatitis A can be severe and lead to liver failure. Some people may need an emergency liver transplant to survive. Hepatitis A doesn’t lead to long-term liver damage or problems, such as cirrhosis.

The most effective way to protect yourself from hepatitis A is to get the hepatitis A vaccine. If you have hepatitis A, you can take steps to prevent spreading hepatitis A to others.

How common is hepatitis A?

Hepatitis A is less common in the United States than in some other parts of the world.

Hepatitis A worldwide

Hepatitis A is most common in areas where sanitation and access to clean water are limited. These areas include parts of Africa, Asia, Central and South America, and Eastern Europe.1

Hepatitis A in the United States

After the hepatitis A vaccine became available in 1995, the number of infections per year went down by more than 95% over the next 20 years.2

In 2022, 2,265 cases of hepatitis A were reported.3 However, many hepatitis A cases aren’t reported.

Who is more likely to get hepatitis A?

People are more likely to get hepatitis A if they

  • travel to countries where hepatitis A is common
  • have sex with an infected person
  • are men who have sex with men
  • use illegal drugs, including injected and noninjected drugs
  • experience homelessness
  • live with or care for someone who has hepatitis A
  • live with or care for a child recently adopted from a country where hepatitis A is common
Male and female tourists taking a picture outdoors.People who travel to countries where hepatitis A is common are more likely to get hepatitis A.

What are the complications of hepatitis A?

People typically recover from hepatitis A without complications. In rare cases, hepatitis A may lead to liver failure. Liver failure due to hepatitis A is more common in older adults and in people who have another liver disease.4

What are the symptoms of hepatitis A?

Some people have symptoms 2 to 7 weeks after they have contact with the virus.4 People with hepatitis A typically get better without treatment after a few weeks. In some cases, symptoms can last up to 6 months.4 These symptoms may include

Some people infected with hepatitis A have no symptoms, including many children younger than age 6 years.3 Older children and adults are more likely to have symptoms.

What causes hepatitis A?

This type of hepatitis is caused by the hepatitis A virus, which spreads through contact with an infected person’s stool. Contact can occur by

  • eating food made by an infected person who didn’t wash their hands after using the bathroom
  • drinking untreated water or eating food washed in untreated water
  • placing a finger or object in your mouth that has had contact with an infected person’s stool
  • having close personal contact with an infected person, such as through sex or caring for someone who is ill

You can’t get hepatitis A from

  • being coughed or sneezed on by an infected person
  • sitting next to an infected person
  • hugging an infected person

A baby can’t get hepatitis A from breast milk.5

How do doctors diagnose hepatitis A?

Doctors diagnose hepatitis A based on symptoms and a blood test.

A health care professional will take a blood sample from you and send the sample to a lab. The lab will check the blood for a specific type of antibody that develops soon after infection with the hepatitis A virus. If your blood has these antibodies, your doctor may diagnose you with acute hepatitis A.

If the blood test finds a different type of hepatitis A antibody, then you are immune to hepatitis A. You may be immune to hepatitis A because you had a past infection or received the vaccine.

How do doctors treat hepatitis A?

To treat hepatitis A symptoms, your doctor may recommend resting, drinking plenty of liquids, and consuming healthy foods and drinks. Your doctor may also suggest medicines to help relieve symptoms.

If you’re diagnosed with hepatitis A, talk with your doctor before taking any prescription or over-the-counter medicines, vitamins or other dietary supplements, or complementary or alternative medicines. Some of these could damage your liver. You should avoid alcohol until your doctor tells you that you have completely recovered from hepatitis A.

Most people recover from hepatitis A on their own within 6 months.6 See your doctor again if you continue to have symptoms after 6 months.

Can I prevent hepatitis A?

You can protect yourself from hepatitis A by getting the hepatitis A vaccine.

If you had hepatitis A in the past, you can’t get hepatitis A again. However, you can still get other types of viral hepatitis.

A vial containing the hepatitis A vaccine, with a stethoscope and other medical equipment in the background. You can protect yourself from hepatitis A by getting the hepatitis A vaccine.

Hepatitis A vaccine

Health care professionals usually give the hepatitis A vaccine in two shots. The second shot is given at least 6 months after the first shot. You need to get both shots to be fully protected against the virus. A combined hepatitis A and hepatitis B vaccine is also available for adults.

Doctors recommend the hepatitis A vaccine for7

  • all children between ages 12 months and 23 months
  • older children who haven’t yet received the vaccine
  • adults who are more likely to get hepatitis A, have chronic liver disease or HIV infection, are traveling to a country where hepatitis A is more common, or want to receive the vaccine

Reduce your chance of infection

If you haven’t been vaccinated against hepatitis A, you can reduce your chance of getting a hepatitis A infection by washing your hands. Wash your hands thoroughly with soap and water for at least 20 seconds

  • after using the toilet
  • after changing diapers
  • before and after handling or preparing food

If you don’t have soap and water available, use a hand sanitizer that is at least 60% alcohol.

If you think you had contact with the hepatitis A virus, see your doctor right away. If taken soon after contact, a dose of the hepatitis A vaccine or a medicine called immune globulin (IG) may protect you from infection.

Your doctor may recommend getting the hepatitis A vaccine or IG if you

  • live with or had sex or close contact with someone who has hepatitis A
  • shared illegal drugs with someone who has hepatitis A
  • ate food or drank water possibly containing the hepatitis A virus

Advice for international travelers

If you’re planning to travel internationally and you haven’t received the hepatitis A vaccine, ask your doctor if you should get the vaccine.

When traveling to countries where hepatitis A is common, choose safer food and drink options, such as bottled water instead of tap water. You can also use bottled water to brush your teeth, make ice cubes, and wash fruits and vegetables. Doctors may also recommend that some travelers take hepatitis A IG.

A smiling man drinking bottled water while outdoors, wearing a backpack, hat, headphones, and sunglasses.When traveling in a country where hepatitis A is common, drink bottled water.

How can I prevent spreading hepatitis A to others?

If you have hepatitis A, you can lower your chance of spreading the infection by washing your hands with soap and water after using the toilet. While you’re sick, avoid close contact with others. Don’t prepare food or serve food to others. Also, tell your doctor, dentist, and other health care professionals that you have hepatitis A.

You’re most contagious—able to spread the virus to others—during the 2 weeks before you have symptoms. You may be contagious for up to 3 weeks after you develop symptoms. Children are often contagious longer than adults.2

What should I eat and drink if I have hepatitis A?

If you have hepatitis A, choose healthy foods and drinks. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

Clinical Trials for Hepatitis A

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 A?

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 A, such as improving hepatitis A vaccination.

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 A are looking for participants?

You can find clinical studies on hepatitis A at ClinicalTrials.gov. In addition to searching for federally funded studies you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health 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.

References

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 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

How common is hepatitis B?

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

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 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 of sexually transmitted disease
  • are men who have sex with men
  • inject drugs
  • have contact with blood, needles, or body fluids at their job
  • have hepatitis C
  • have been on kidney 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.

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. 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.

A health care professional taking a medical history from a young Asian woman. Doctors recommend all adults be screened for hepatitis B at least once in their lifetime.

What are the complications of hepatitis B?

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 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 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

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.

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 encounter the virus.1 These symptoms may include

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

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 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.

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, 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.

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 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.
  • ultrasound or 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.

How do doctors treat hepatitis B?

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.

How do doctors treat the complications of hepatitis B?

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.

How can I protect myself from hepatitis B infection?

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.

A health care professional giving a vaccine to an infant. Doctors most often give the hepatitis B vaccine in three shots over 6 months.

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

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. 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.

A baby in a hospital bassinet. If you are pregnant and have hepatitis B, your baby should receive the hepatitis B vaccine and HBIG right after birth.

What should I eat and drink if I have hepatitis B?

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.

Clinical Trials for Hepatitis B

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.

References

Hepatitis C

In this section:

What is hepatitis C?

Hepatitis C 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 C virus spreads through contact with an infected person’s blood.

Although no vaccine is available, you can take steps to protect yourself from hepatitis C. If you have hepatitis C, talk with your doctor about treatment. Medicines can cure most cases of hepatitis C.

Hepatitis C can cause an acute or chronic infection.

Acute hepatitis C

Acute hepatitis C is an infection that only lasts a short time, and then the virus goes away. An infection may be diagnosed weeks or months after you encounter the hepatitis C virus.1

Chronic hepatitis C

Chronic hepatitis C is a long-lasting infection. Chronic hepatitis C occurs when the hepatitis C virus stays in your body and doesn’t go away. More than half of the people with acute hepatitis C will develop chronic hepatitis C.1

Early diagnosis and treatment of chronic hepatitis C can prevent liver damage. Without treatment, chronic hepatitis C can cause chronic liver disease, cirrhosis, liver failure, or liver cancer.

How common is hepatitis C?

Hepatitis C is less common in the United States than in some other parts of the world.

Hepatitis C worldwide

Hepatitis C infections are more common in some countries in Eastern Europe, Africa, the Middle East, and Asia. In countries where hepatitis C is most common, researchers estimate that between 2% and 6% of the population is infected.2

Hepatitis C in the United States

Researchers estimate that less than 1% of the United States population is infected with hepatitis C.2

The number of new acute hepatitis C infections declined in 2022. There were 4,848 new infections reported, with most occurring in people who inject drugs.3 However, many hepatitis C cases aren’t reported because people often have no symptoms.

In the United States, hepatitis C is the most common chronic viral infection found in blood and spread through contact with blood.4 New screening efforts and more effective hepatitis C treatments are helping health care professionals identify and cure more people with the disease. The number of people with chronic hepatitis C in the United States is decreasing because effective therapies are available. However, researchers estimate chronic hepatitis C still affects more than 2 million people.1

Who is more likely to get hepatitis C?

Hepatitis C is more common in people who

  • inject drugs or have injected drugs in the past
  • are infected with HIV
  • have been on kidney dialysis
  • received donated blood, blood products, or an organ before 1992
  • have hemophilia and received clotting factor before 1987
  • have been in contact with blood or needles and syringes at work
  • were born to a mother with hepatitis C
  • were born in a country where hepatitis C is common

In the United States, injecting drugs is the most common way that people get hepatitis C.5

Should I be screened for hepatitis C?

Screening is testing for a disease in people who have no symptoms. Doctors use blood tests to screen for hepatitis C. Many people who have hepatitis C don’t have symptoms and don’t know they are infected. Screening tests can help doctors diagnose and treat hepatitis C before it causes serious health problems.

Doctors typically recommend hepatitis C screening for5

  • all adults at least once in their life
  • pregnant women during each pregnancy
  • people who are at risk for hepatitis C infection
  • anyone who asks to be screened for hepatitis C
A large, multicultural group of men and women of all ages. Doctors typically recommend hepatitis C screenings at least once for all adults.

What are the complications of hepatitis C?

Hepatitis C may lead to serious complications. Early diagnosis and treatment can help prevent complications.

Acute hepatitis C complications

Acute hepatitis C typically doesn’t cause serious complications. However, more than half of people with acute hepatitis C will develop chronic hepatitis C.1 Chronic hepatitis C can lead to serious complications if left untreated.

Chronic hepatitis C complications

Chronic hepatitis C 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. People with cirrhosis have a higher chance of developing liver cancer. 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.

What are the symptoms of hepatitis C?

Most people infected with hepatitis C have few or no symptoms. Some people with an acute hepatitis C infection may have symptoms 2 to 12 weeks after they encounter the virus.1 These symptoms may include

People with chronic hepatitis C likely will have few or no symptoms until complications such as cirrhosis develop, which could be decades after they were infected. For this reason, screening can help find hepatitis C infections in people without 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

What causes hepatitis C?

The hepatitis C virus causes hepatitis C. The hepatitis C virus spreads through contact with an infected person’s blood. Contact can occur by

  • 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
  • being born to a mother with hepatitis C
  • having unprotected sex with an infected person
  • having dental or medical procedures with needles or other tools that aren’t properly cleaned in countries where hepatitis C is common

You can’t get hepatitis C from

  • being coughed or sneezed on by an infected person
  • drinking water or eating food
  • hugging an infected person
  • shaking hands or holding hands with an infected person
  • sharing spoons, forks, and other eating utensils with an infected person
  • sitting next to an infected person

A baby can’t get hepatitis C from breast milk.6 However, you should avoid breastfeeding if your nipples are cracked or bleeding.

How do doctors diagnose hepatitis C?

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

Medical history

Your doctor will ask about your symptoms. They will also ask whether you have any history of blood transfusions, injection drug use, and other risk factors.

Physical exam

During a physical exam, your doctor will typically examine your body to 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

Blood tests

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

Certain types of blood tests for hepatitis C can show

  • whether you had contact with the hepatitis C virus at some point
  • whether you still have the hepatitis C virus
  • how much of the virus is in your blood
  • what form of hepatitis C you have

Your doctor may also order blood tests while you are getting treatment. Blood tests can show whether the treatment is changing the amount of virus in your blood.

A health care professional taking a blood sample from a patient. Your doctor may order one or more blood tests to diagnose hepatitis C.

Additional tests

If you have chronic hepatitis C, you could have liver damage. Before starting treatment, doctors will test for liver damage and other infections, such as HIV and hepatitis B. Your doctor may recommend ongoing testing to check for signs of complications.

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.
  • ultrasound or other imaging test to check for cirrhosis.
  • liver biopsy, in which a doctor uses a needle to take a small piece of tissue from the liver.

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

How do doctors treat hepatitis C?

A woman taking a pill. Doctors treat hepatitis C with antiviral medicines that attack the virus.

If the hepatitis C virus doesn’t go away on its own within 6 months, you will likely need treatment. Doctors treat hepatitis C with antiviral medicines that attack the virus.

Antiviral medicines can cure more than 95% of people with chronic hepatitis C in 8 to 12 weeks.7 However, some people may need to take antiviral medicines for longer.

Hepatitis C medicines are usually well tolerated, but they may cause side effects in some people. Talk with your doctor about the possible side effects of hepatitis C treatment.

Check with your doctor before taking any other prescription or over-the-counter medicines. For safety reasons, talk with your doctor before using dietary supplements, such as vitamins, or any complementary or alternative medicines or medical practices. Some of these could lead to liver damage and may interact with hepatitis C medicines.

Cost of hepatitis C medicines

Medicines for hepatitis C can be costly. Most government and private health insurance prescription drug plans provide some coverage for these medicines. Talk with your doctor about your health insurance coverage for hepatitis C medicines.

Drug companies, nonprofit organizations, and some states offer programs that can help pay for hepatitis C medicines. If you need help paying for medicines, talk with your doctor. Learn more about financial help for hepatitis C medicines.

How do doctors treat the complications of hepatitis C?

If hepatitis C leads to cirrhosis, see a doctor who has experience treating people with 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 hepatitis C leads to liver failure or liver cancer, you may need a liver transplant.

How can I protect myself from hepatitis C infection?

If you don’t have hepatitis C, you can help protect yourself from hepatitis C 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 and unopened ink
  • not sharing personal items such toothbrushes, razors, or nail clippers

Hepatitis C can spread from person to person during sex, but the chances are low. Some people have a higher risk of getting hepatitis C during sex. Higher risk groups include men who have sex with men and people who have multiple sex partners, have HIV or other sexually transmitted diseases, or engage in rough sex. Talk with your doctor about your risk of getting hepatitis C through sex and about safe sex practices. For example, using a latex or polyurethane condom may help prevent the spread of hepatitis C.

Two syringes. Don’t share drug needles or other drug materials.

If you had hepatitis C in the past, you can get hepatitis C again. Follow the steps above and talk with your doctor about how to protect yourself from another hepatitis C infection.

If you think you may have been exposed to the hepatitis C virus, see your doctor as soon as possible. Early diagnosis and treatment can help prevent liver damage.

How can I prevent spreading hepatitis C to others?

If you have hepatitis C, follow the steps above to avoid spreading the infection. Tell your sex partner you have hepatitis C and talk with your doctor about safe sex practices.

You can also protect others from infection by telling your doctor, dentist, and other health care professionals that you have hepatitis C. Don’t donate blood or blood products, semen, or tissue.

Is a hepatitis C vaccine available?

Researchers are still working on a vaccine for hepatitis C. If you have hepatitis C, talk with your doctor about vaccines for infections that could further damage your liver, such as hepatitis A and hepatitis B.

What should I eat and drink if I have hepatitis C?

If you have hepatitis C, choose healthy foods and drinks. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

Clinical Trials for Hepatitis C

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 C?

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 C, such as

  • the progression and outcomes of hepatitis C
  • better hepatitis C prevention and treatment for people who inject drugs
  • treatment for hepatitis C during pregnancy

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 C are looking for participants?

You can view a filtered list of clinical studies on hepatitis C 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, 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.

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

NIDDK and NIH have conducted and supported many research projects to learn more about hepatitis C, including

  • the molecular structure of the hepatitis C virus
  • interferon alpha, the first treatment for chronic hepatitis C
  • the hepatitis C virus that was grown in a lab, which helped to develop new hepatitis C treatments

References

Hepatitis D

In this section:

What is hepatitis D?

Hepatitis D 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 D virus is unusual because it can only infect people who also have hepatitis B virus infection. In this way, hepatitis D is a double infection. You can protect yourself from hepatitis D by protecting yourself from hepatitis B. The best way to prevent hepatitis B is by getting the hepatitis B vaccine.

Hepatitis D spreads the same way that hepatitis B spreads: through contact with an infected person’s blood or other body fluids.

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

Acute hepatitis D

Acute hepatitis D is an infection that only lasts a short time, and then the virus goes away. The symptoms of acute hepatitis D are the same as the symptoms of other types of hepatitis, but they are often more severe.1

Chronic hepatitis D

Chronic hepatitis D is a long-lasting infection. Chronic hepatitis D occurs when the hepatitis D virus stays in your body and doesn’t go away. People who have chronic hepatitis B and hepatitis D together develop complications more often and more quickly than people who have chronic hepatitis B alone.2

How do hepatitis D and hepatitis B infections occur together?

People can only become infected with hepatitis D when they also have hepatitis B. Hepatitis D and hepatitis B infections may occur together as a coinfection or a superinfection.

A coinfection occurs when a person gets hepatitis B and hepatitis D at the same time. If a person already has hepatitis B and then gets hepatitis D, it’s called a superinfection. A coinfection and superinfection can both cause severe acute hepatitis.

Less than 5% of adults with a coinfection will develop both chronic hepatitis B and chronic hepatitis D. However, up to 90% of adults with a superinfection will go on to develop both chronic hepatitis B and chronic hepatitis D.3

How common is hepatitis D?

Hepatitis D is less common in the United States than in other parts of the world.

Hepatitis D worldwide

Hepatitis D is more common in Eastern and Southern Europe, the Mediterranean region and Middle East, parts of Asia, West and Central Africa, and parts of South America.

Hepatitis D in the United States

It’s unknown exactly how many people in the United States have hepatitis D, but some research suggests 3% to 5% of adults with hepatitis B are also infected with hepatitis D.4,5 Most cases are among people who have lived in countries where hepatitis D is more common.6

Who is more likely to get hepatitis D?

People are more likely to get hepatitis D if they

  • are already infected with hepatitis B
  • have HIV
  • inject drugs or have injected drugs in the past
  • have lived with or had sex with someone who has hepatitis D
  • are men who have sex with men
  • are from an area of the world where hepatitis D is more common
  • have multiple sex partners or a history of sexually transmitted disease

What are the complications of hepatitis D?

Compared with people infected with hepatitis B alone, people infected with both hepatitis D and B are more likely to develop complications.1 Early diagnosis and treatment may lower your chances of having complications.

Acute hepatitis D complications

In rare cases, acute hepatitis D 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 D complications

Chronic hepatitis D may 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 an ultrasound or another type of imaging test to check for liver cancer. Finding cancer at an early stage improves the chances of curing the cancer.

What are the symptoms of hepatitis D?

Most people with acute hepatitis D have symptoms, which may include

  • darker urine color and lighter stool color
  • fatigue, or feeling tired
  • fever
  • joint pain
  • loss of appetite, nausea, or vomiting
  • pain in the abdomen
  • yellow tint to the eyes and skin, called jaundice

In contrast, most people with chronic hepatitis D have few symptoms until complications such as cirrhosis develop, which could be several years or decades after becoming infected. 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

What causes hepatitis D?

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

  • sharing needles or other materials used to inject drugs with an infected person
  • having unprotected sex with an infected person
  • getting an accidental stick with a needle that was 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 D 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
  • sharing drinks or food with an infected person
  • hugging an infected person
  • shaking hands or holding hands with an infected person
  • sharing spoons, forks, and other eating utensils with an infected person
  • sitting next to an infected person

The hepatitis D virus rarely spreads from mother to child during birth. Mothers who have hepatitis B and hepatitis D can safely breastfeed their babies if steps are taken shortly after birth to prevent spreading the hepatitis B infection. However, you should avoid breastfeeding if your nipples are cracked or bleeding.

How do doctors diagnose hepatitis D?

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

Medical history

Your doctor will ask about your symptoms and factors that may make you more likely to get hepatitis D.

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 D. A health care professional will take a blood sample from you and send the sample to a lab.

A health care professional collecting blood from a patient. Your doctor may order one or more blood tests to diagnose hepatitis D.

Additional tests

If you have chronic hepatitis D and hepatitis B, you could have liver damage. Your doctor may recommend getting tested regularly to check for signs of liver damage, how much of your liver is damaged, or to rule out other causes of liver disease. These 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.
  • ultrasound or other imaging test 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 liver damage or disease. Talk with your doctor about which tests are best for you.

How do doctors treat hepatitis D?

No medicines have been approved to treat hepatitis D in the United States. In some cases, doctors may recommend medicines called interferons, which are sometimes used to treat other forms of viral hepatitis. Researchers are studying treatments for hepatitis D.

People who have hepatitis D also have hepatitis B and may need hepatitis B treatments.

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.

How do doctors treat the complications of hepatitis D?

If chronic hepatitis D leads to cirrhosis, see a doctor who is an expert in liver diseases. Doctors can treat 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 imaging tests to check for liver cancer.

If hepatitis D 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, which will also prevent hepatitis D.

How can I protect myself from hepatitis D infection?

If you don’t have hepatitis B, you can prevent hepatitis D infection by taking steps to prevent hepatitis B infection, such as getting the hepatitis B vaccine. If you don’t get hepatitis B, you can’t get hepatitis D.

If you already have hepatitis B, you can take steps to prevent hepatitis D 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
  • not sharing personal items such as toothbrushes, razors, or nail clippers
  • using a latex or polyurethane condom during sex

How can I prevent spreading hepatitis D to others?

If you have hepatitis D, follow the steps above to avoid spreading the infection.

Preventing hepatitis B will also prevent hepatitis D. Your sex partners should get a hepatitis B test. If they aren’t infected, they should get the hepatitis B vaccine. Taking steps to prevent spreading hepatitis B to a baby will also help prevent hepatitis D infection.

You can also protect others from getting infected by telling your doctor, dentist, and other health care professionals that you have hepatitis D. Don’t donate blood or blood products, semen, organs, or tissue.

Is a hepatitis D vaccine available?

No vaccine for hepatitis D is currently available. The hepatitis B vaccine can prevent hepatitis D by preventing hepatitis B.

What should I eat and drink if I have hepatitis D?

If you have hepatitis D, choose healthy foods and drinks. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

Clinical Trials for Hepatitis D

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 D?

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 D, such as the progression, treatment, and outcomes of chronic hepatitis D.

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 D are looking for participants?

You can find clinical studies on hepatitis D at ClinicalTrials.gov. In addition to searching for federally funded studies, you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health 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 D from NIDDK-funded research?

NIDDK has supported many research projects to learn more about hepatitis D, such as projects exploring new hepatitis D treatments and 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 and hepatitis D affect children and adults and explored new approaches to diagnosis and treatment.

References

Hepatitis E

In this section:

What is hepatitis E?

Hepatitis E 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. The hepatitis E virus has different forms, called genotypes, that spread in different ways.

The most common hepatitis E genotypes are spread by drinking contaminated water. Rarer genotypes infect pigs and some wild animals. People may become infected by these genotypes if they eat undercooked pork or wild game, such as boar and deer. People may also become infected if they consume water that has come in contact with stool from an infected animal.

There is currently no vaccine available for hepatitis E in the United States. You can take steps to protect yourself from hepatitis E. In the United States, hepatitis E is not commonly spread from person to person.

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

Acute hepatitis E

The hepatitis E virus usually causes an acute infection. Acute hepatitis E is an infection that only lasts a short time, and then the virus goes away. In some cases, acute hepatitis E can be severe and lead to problems, such as acute liver failure.

Chronic hepatitis E

Chronic hepatitis E is a long-lasting infection. Chronic hepatitis E occurs when the virus stays in your body and doesn’t go away.

Chronic hepatitis E is rare and typically occurs only in developed nations. Most people with chronic hepatitis E have weakened immune systems. This may include people who are receiving certain cancer treatments, are taking medicines to prevent organ transplant rejection, or have HIV.1,2

How common is hepatitis E?

Hepatitis E is the most common type of viral hepatitis in the world. Different hepatitis E genotypes are less common in the United States than in some other parts of the world.

Hepatitis E worldwide

The most common hepatitis E genotypes—which are spread by drinking contaminated water— are more common where sanitation and access to clean water are limited, including parts of Asia, Africa, and Central America. The World Health Organization estimates that more than 20 million people around the world are infected every year.3

Hepatitis E in the United States

Rarer hepatitis E genotypes spread in the United States and some other developed nations. These genotypes are spread by eating undercooked pork or wild game or by consuming water that has come in contact with stool from an infected animal.

Research suggests that up to 21% of people in the United States have been infected with hepatitis E at some point in their lives.4 Most people don’t know they had been infected because they had no symptoms.

Who is more likely to have hepatitis E symptoms?

The forms of hepatitis E that are common in developing nations are more likely to cause symptoms in people between ages 15 and 44.1 Children are also affected by these forms of hepatitis E, but many have mild or no symptoms.

The forms of hepatitis E that affect people in some developed nations most often cause no symptoms. However, men over age 60 and people with weakened immune systems are more likely to have hepatitis E symptoms.4 Hepatitis E infection is also more common in people who have hepatitis C and other chronic liver diseases.

What are the complications of hepatitis E?

Acute hepatitis E complications

People with acute hepatitis E most often get better without complications.

In some severe cases, acute hepatitis E may cause acute liver failure, a condition in which the liver suddenly stops working properly. Acute liver failure due to hepatitis E is more common in developing nations and in certain groups, including

  • pregnant women
  • people who have other liver diseases

Hepatitis E can cause other complications for women and their babies, such as stillbirth, premature birth, or low birthweight.

Chronic hepatitis E complications

Although chronic hepatitis E is rare, it can lead to health problems such as cirrhosis or liver failure.

What are the symptoms of hepatitis E?

Many people infected with hepatitis E have no symptoms. Other people begin to have symptoms 15 to 60 days after they become infected with the virus.1 These symptoms can include

  • darker urine color and lighter stool color
  • fatigue, or feeling tired
  • fever
  • joint pain
  • loss of appetite, nausea, and vomiting
  • pain in the abdomen
  • yellow tint to the eyes and skin, called jaundice

People with hepatitis E typically get better without treatment after several weeks.

What causes hepatitis E?

The hepatitis E virus causes hepatitis E. In nations where access to clean water is limited, hepatitis E typically spreads when people drink untreated water. Water can become contaminated when it comes in contact with stool from people who are infected with the virus.

In the United States and some other developed nations, hepatitis E can spread when people eat food contaminated with the virus, such as raw or undercooked pork or deer meat. Hepatitis E may also spread when people consume water that has come in contact with stool from an infected animal.

Research suggests that hepatitis E can also spread through blood transfusion, but this is very rare.5

How do doctors diagnose hepatitis E?

Doctors diagnose hepatitis E based on symptoms and blood tests. A health care professional will take a blood sample from you and send the sample to a lab. Blood tests can detect antibodies to the hepatitis E virus and show whether you have had hepatitis E.

A health care professional talking with a patient. Doctors diagnose hepatitis E based on symptoms and a blood test.

How do doctors treat hepatitis E?

To treat acute hepatitis E symptoms, your doctor may suggest getting plenty of rest, drinking plenty of liquids, and consuming healthy foods and drinks. In some cases, doctors prescribe medicines to treat chronic hepatitis E. See your doctor regularly to make sure you have fully recovered.

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. You should also avoid alcohol until your doctor tells you that you have completely recovered from hepatitis E.

Is a hepatitis E vaccine available?

No vaccine for hepatitis E is available in the United States. Vaccines have been developed and are used in China.

How can I protect myself from hepatitis E infection?

When traveling in a developing nation, drink bottled water and use it to brush your teeth, make ice cubes, and wash fruits and vegetables.

Also, make sure any meat you eat is thoroughly cooked, both in developing nations and in developed nations, such as the United States.

The bottled water aisle of a store with an arm coming in from the right side of the frame to select a bottle. When traveling in a developing nation, drink bottled water.

How can I prevent spreading hepatitis E to others?

It’s uncommon for people to spread hepatitis E directly to other people. If you have hepatitis E, you can reduce your chance of spreading the infection by washing your hands with soap and water after using the toilet and before preparing food. If you don’t have soap and water available, use a hand sanitizer that is at least 60% alcohol. Talk with a blood donation center before you donate blood.

What should I eat and drink if I have hepatitis E?

If you have hepatitis E, you should choose healthy food and drinks. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

Clinical Trials for Hepatitis E

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 E?

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.

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 E are looking for participants?

You can find clinical studies on hepatitis E at ClinicalTrials.gov. In addition to searching for federally funded studies, you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health 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.

References

Last Reviewed December 2024
Share this page
Facebook X Email WhatsApp LinkedIn Reddit Pinterest

This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.

NIDDK would like to thank:
Paul Martin, M.D., University of Miami Miller School of Medicine; Anna Suk-Fong Lok, M.D., University of Michigan; Jordan Feld, M.D., MPH, Toronto General Hospital; and Kenneth Sherman, M.D., Ph.D., University of Cincinnati