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.

Hepatitis A and hepatitis E typically spread through contact with food or water that has been contaminated by an infected person’s stool. People may also get hepatitis E by eating undercooked pork, deer, or shellfish.

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 sharing drug needles or having unprotected sex.

The hepatitis A and E viruses typically cause only acute, or short-term, infections. In an acute infection, your body is able to fight off the infection and the virus goes away.

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

When doctors can’t find the cause of a person’s hepatitis, they may call this condition non-A–E hepatitis or hepatitis X. Experts think that unknown viruses other than hepatitis A, B, C, D, and E may cause some cases of hepatitis. Researchers are working to identify these viruses.

Although non-A–E hepatitis is most often acute, it can become chronic.

Hepatitis A

In this section:

What is hepatitis A?

Hepatitis A 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 normal cells in your body. Many viruses cause infections that can be spread from person to person. The hepatitis A virus typically spreads through contact with food or water that has been contaminated by an infected person’s stool.

Hepatitis A is an acute or short-term infection, which means people usually get better without treatment after a few weeks. In rare cases, hepatitis A can be severe and lead to liver failure and the need for an emergency liver transplant to survive. Hepatitis A does not lead to long-term complications, such as cirrhosis, because the infection only lasts a short time.

You can take steps to protect yourself from hepatitis A, including getting 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?

In the United States, hepatitis A has become relatively uncommon. After the hepatitis A vaccine became available in 1995, the rate of hepatitis A infections declined by 95 percent in the United States. The number of reported cases of hepatitis A fell to 1,239 in 2014, the lowest yearly number of cases reported since the disease could be tracked.1 However, the number of reported cases increased to 3,366 in 2017, almost 3 times higher, mostly due to outbreaks among people who use drugs and people experiencing homelessness.1 Early reports suggest that the numbers of cases and outbreaks of hepatitis A increased further during 2018 and continue at these higher rates in 2019.2

Hepatitis A is more common in developing countries where sanitation is poor and access to clean water is limited. Hepatitis A is more common in parts of Africa, Asia, Central and South America, and Eastern Europe than it is in the United States.

Who is more likely to get hepatitis A?

People more likely to get hepatitis A are those who

  • travel to developing countries
  • have sex with an infected person
  • are men who have sex with men
  • use illegal drugs, including drugs that are not injected
  • experience unstable housing or 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
Tourists in a row boat on a river.
People who travel to developing countries 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 adults older than age 50 and in people who have another liver disease.3

What are the symptoms of hepatitis A?

Some people have symptoms 2 to 7 weeks after they come in contact with the virus.3 People with hepatitis A typically get better without treatment after a few weeks. In some cases, symptoms can last up to 6 months. These symptoms may include

Some people infected with hepatitis A have no symptoms, including many children younger than age 6.3 Older children and adults are more likely to have symptoms.

What causes hepatitis A?

The hepatitis A virus causes this type of hepatitis and spreads through contact with an infected person’s stool. Contact can occur by

  • eating food made by an infected person who did not wash his or her hands after using the bathroom
  • drinking untreated water or eating food washed in untreated water
  • placing a finger or an object in your mouth that came into 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 cannot get hepatitis A from

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

A baby cannot get hepatitis A from breast milk.4

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. A blood test will detect antibodies to the hepatitis A virus called immunoglobulin M (IgM) antibodies and show whether you have acute hepatitis A. If the blood test finds antibodies to the hepatitis A virus that are not IgM antibodies, then you are immune to hepatitis A, due to either past hepatitis A infection or hepatitis A vaccination.

How do doctors treat hepatitis A?

Treatment includes resting, drinking plenty of liquids, and eating healthy foods to help relieve symptoms. Your doctor may also suggest medicines to help relieve symptoms.

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

See your doctor regularly to make sure your body has fully recovered. If you have symptoms for longer than 6 months, see your doctor again.

How can I protect myself from hepatitis A infection?

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

If you have had hepatitis A in the past, you cannot get hepatitis A again. You can still get other types of viral hepatitis though.

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

Hepatitis A vaccine

All children should receive the hepatitis A vaccine between 12 and 23 months of age. People who are more likely to be infected and people with chronic liver disease should also receive the vaccine.

Doctors give the hepatitis A vaccine in two shots. You should get the second shot 6 to 12 months after the first shot. You need to get both shots to be fully protected against the virus.

If you are traveling to a developing country where hepatitis A is common and you haven’t received the hepatitis A vaccine, talk with your doctor about how to prevent getting hepatitis A. If possible, try to get both shots of the hepatitis A vaccine before you go. If you don’t have time to get both shots, get the first shot as soon as you can. Most people gain some protection within 2 weeks of the first shot.

Reduce your chance of infection

You can reduce your chance of getting hepatitis A by washing your hands thoroughly with soap and warm water for 15 to 30 seconds

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

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

Bottled water.
When traveling in a developing country, drink bottled water.

Prevent infection after contact with the virus

If you think you have come in contact with the hepatitis A virus, see your doctor right away. A dose of the hepatitis A vaccine or a medicine called hepatitis A immune globulin may protect you from getting the infection. Your doctor may recommend a vaccine dose or medicine if

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

You must get the vaccine dose or medicine shortly after coming into contact with the virus to prevent infection.

How can I prevent spreading hepatitis A to others?

If you have hepatitis A, you can reduce your chance of spreading the infection by washing your hands with warm, soapy water after using the toilet and before fixing or eating food. While you are sick, avoid close contact with others, and don’t prepare food or serve food to others. Also, tell your doctor, dentist, and other health care professionals that you have hepatitis A.

Talk with a blood donation center before you donate blood. If you had hepatitis A when you were younger than 11, you may be able to donate blood. If you had hepatitis A when you were age 11 or older, you should not donate blood.

You are 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.5

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

If you have hepatitis A, you should eat a balanced, healthy diet. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

References

Hepatitis B

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 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.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

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 you9,14

  • 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. 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

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

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.

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

A medicine that doctors can give as a shot is peginterferon alfa-2a (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, such as vitamins, or any complementary or alternative medicines 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. 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 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—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.

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. 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). 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.

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 normal cells in your body. Many viruses cause infections that can be spread from person to person. The hepatitis C virus spreads through contact with an infected person’s blood.

Hepatitis C can cause an acute or chronic infection.

Although no vaccine for hepatitis C 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.

Acute hepatitis C

Acute hepatitis C is a short-term infection. Symptoms can last up to 6 months. Sometimes your body is able to fight off the infection and the virus goes away.

Chronic hepatitis C

Chronic hepatitis C is a long-lasting infection. Chronic hepatitis C occurs when your body isn’t able to fight off the virus. About 75 to 85 percent of people with acute hepatitis C will develop chronic hepatitis C.13

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 in the United States?

In the United States, hepatitis C is the most common chronic viral infection found in blood and spread through contact with blood.14

Researchers estimate that about 2.7 million to 3.9 million people in the United States have chronic hepatitis C.13 Many people who have hepatitis C don’t have symptoms and don’t know they have this infection.

Since 2006, the number of new hepatitis C infections has been rising, especially among people younger than age 30 who inject heroin or misuse prescription opioids and inject them.15,16

New screening efforts and more effective hepatitis C treatments are helping doctors identify and cure more people with the disease. With more screening and treatment, hepatitis C may become less common in the future. Researchers estimate that hepatitis C could be a rare disease in the United States by 2036.17

Who is more likely to get hepatitis C?

People more likely to get hepatitis C are those who

  • have injected drugs
  • had a blood transfusion or organ transplant before July 1992
  • have hemophilia and received clotting factor before 1987
  • have been on kidney dialysis
  • have been in contact with blood or infected needles at work
  • have had tattoos or body piercings
  • have worked or lived in a prison
  • were born to a mother with hepatitis C
  • are infected with HIV
  • have had more than one sex partner in the last 6 months or have a history of sexually transmitted disease
  • are men who have or had sex with men

In the United States, injecting drugs is the most common way that people get hepatitis C.13

Should I be screened for hepatitis C?

Doctors usually recommend one-time screening of all adults ages 18 to 79 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 have hepatitis C. Screening tests can help doctors diagnose and treat hepatitis C before it causes serious health problems.

A large, multicultural group of men and women of all ages.
Doctors usually recommend one-time screening of all adults ages 18 to 79 for hepatitis C.

What are the complications of hepatitis C?

Without treatment, hepatitis C may lead to cirrhosis, liver failure, and liver cancer. Early diagnosis and treatment of hepatitis C can prevent these complications.

Cirrhosis

Cirrhosis is a condition in which the liver slowly breaks down and is unable to function normally. Scar tissue replaces healthy liver tissue and partially blocks the flow of blood through the liver. In the early stages of cirrhosis, the liver continues to function. However, as cirrhosis gets worse, the liver begins to fail.

Liver failure

Also called end-stage liver disease, liver failure progresses over months, years, or even decades. With end-stage liver disease, the liver can no longer perform important functions or replace damaged cells.

Liver cancer

Having chronic hepatitis C increases your chance of developing liver cancer. If chronic hepatitis C causes severe liver damage or cirrhosis before you receive hepatitis C treatment, you will continue to have an increased chance of liver cancer even after treatment. 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 no symptoms. Some people with an acute hepatitis C infection may have symptoms within 1 to 3 months after they are exposed to the virus. These symptoms may include

If you have chronic hepatitis C, you most likely will have no symptoms until complications develop, which could be decades after you were infected. For this reason, hepatitis C screening is important, even if you have no symptoms.

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 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 or inks that were not kept sterile—free from all viruses and other microorganisms—and were used on an infected person before they were used on you 
  • 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

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
  • sitting next to an infected person

A baby can’t get hepatitis C from breast milk.18

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 and whether you have any history of blood transfusions or injected drug use.

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

What tests do doctors use to diagnose hepatitis C?

Doctors use blood tests to diagnose hepatitis C. 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 C. A health care professional will take a blood sample from you and send the sample to a lab.

Blood tests for hepatitis C include the following:

  • Screening test for antibodies to the hepatitis C virus. A screening blood test will show whether you have developed antibodies to the hepatitis C virus. A positive antibody test means you were exposed to the hepatitis C virus at some point. However, the virus may no longer be present in your blood if your body fought off the infection on its own or if you received treatment that cured the infection.
  • Hepatitis C RNA test. If your antibody test is positive, your doctor will use a hepatitis C RNA test to detect RNA—a type of genetic material—from the hepatitis C virus. The hepatitis C RNA test can show whether you still have the hepatitis C virus and how much virus is in your blood. This information can help your doctor treat the infection. To see if you are responding to treatment, your doctor may order this test while you are undergoing treatment to find out if the amount of virus in your blood is changing.
  • Genotype test. Your doctor can use this test to find out what strain, or form, of hepatitis C virus you have. At least six specific strains—called genotypes—of hepatitis C exist. Genotype 1 is the most common hepatitis C genotype in the United States.1 Your doctor will recommend treatment based on which hepatitis C genotype you have.
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’ve had chronic hepatitis C for 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 C?

Doctors treat hepatitis C with antiviral medicines that attack the virus and can cure the disease in most cases.

Several newer medicines, called direct-acting antiviral medicines, have been approved to treat hepatitis C since 2013. Studies show that these medicines can cure chronic hepatitis C in most people with this disease. These medicines can also cure acute hepatitis C. In some cases, doctors recommend waiting to see if an acute infection becomes chronic before starting treatment.

Your doctor may prescribe one or more of these newer, direct-acting antiviral medicines to treat hepatitis C:

Newer medicines are sometimes used along with these older hepatitis C medicines:

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

You may need to take medicines for 8 to 24 weeks to cure hepatitis C. Your doctor will prescribe medicines and recommend a length of treatment based on

  • which hepatitis C genotype you have
  • how much liver damage you have
  • whether you have been treated for hepatitis C in the past

Your doctor may order blood tests during and after your treatment. Blood tests can show whether the treatment is working. Hepatitis C medicines cure the infection in most people who complete treatment.

Hepatitis C medicines may cause side effects. Talk with your doctor about the side effects of 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.

Cost of hepatitis C medicines

The newer direct-acting antiviral 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, you should see a doctor who specializes in liver diseases. Doctors can treat the health problems related to cirrhosis with medicines, surgery, and other medical procedures. If you have cirrhosis, you have an increased chance of liver cancer. Your doctor may order an ultrasound 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 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 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. People who have multiple sex partners, have HIV or other sexually transmitted diseases, or who engage in rough or anal sex have a higher chance of getting hepatitis C. Talk with your doctor about your risk of getting hepatitis C through sex and about safe sex practices, such as using a latex or polyurethane condom to help prevent the spread of hepatitis C. 

Two syringes with needles.
Do not share drug needles or other drug materials.

If you had hepatitis C in the past and your body fought off the infection or medicines cured the infection, 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. In addition, you can protect others from infection by telling your doctor, dentist, and other health care providers that you have hepatitis C. Don’t donate blood or blood products, semen, organs, 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 hepatitis A and hepatitis B. These vaccines can protect you from hepatitis A and hepatitis B infections, which could further damage your liver.

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

If you have hepatitis C, you should eat a balanced, healthy diet. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

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 normal 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 you when you also have a 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 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, or both. 

Acute hepatitis D

Acute hepatitis D is a short-term infection. The symptoms of acute hepatitis D are the same as the symptoms of any type of hepatitis and are often more severe.19 Sometimes your body is able to fight off the infection and the virus goes away.

Chronic hepatitis D

Chronic hepatitis D is a long-lasting infection. Chronic hepatitis D occurs when your body is not able to fight off the virus and the virus does not go away. People who have chronic hepatitis B and D develop complications more often and more quickly than people who have chronic hepatitis B alone.20

How do hepatitis D and hepatitis B infections occur together?

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

Coinfection

A coinfection occurs when you get both hepatitis D and hepatitis B infections at the same time. Coinfections usually cause acute, or short-term, hepatitis D and B infections. Coinfections may cause severe acute hepatitis.

In most cases, people are able to recover from and fight off the acute hepatitis D and B infections and the viruses go away. However, in less than 5 percent of people with a coinfection, both infections become chronic and do not go away.21

Superinfection

A superinfection occurs if you already have chronic hepatitis B and then become infected with hepatitis D. When you get a superinfection, you may have severe acute hepatitis symptoms.19

Up to 90 percent of people with a superinfection are not able to fight off the hepatitis D virus, and develop chronic hepatitis D.20 As a result, these people will have both chronic hepatitis D and chronic hepatitis B.

How common is hepatitis D?

Hepatitis D is not common in the United States. Hepatitis D is more common in other parts of the world, including Eastern and Southern Europe; the Mediterranean region and Middle East; parts of Asia, including Mongolia; Central Africa; and the Amazon River basin in South America.22,23

Who is more likely to have hepatitis D?

Hepatitis D infection occurs only in people who have hepatitis B. People are more likely to have hepatitis D in addition to hepatitis B if they

What are the complications of acute hepatitis D?

In rare cases, acute hepatitis D can lead to acute liver failure, a condition in which the liver fails suddenly. Although acute liver failure is uncommon, hepatitis D and B infections are more likely to lead to acute liver failure than hepatitis B infection alone.24

What are the complications of chronic hepatitis D?

Chronic hepatitis D may lead to cirrhosis, liver failure, and liver cancer. People who have chronic hepatitis B and D are more likely to develop these complications than people who have chronic hepatitis B alone.20 Early diagnosis and treatment of chronic hepatitis B and D can lower your chances of developing serious health problems.

Cirrhosis

Cirrhosis is a condition in which the liver slowly breaks down and is unable to work normally. Scar tissue replaces healthy liver tissue, partly blocking the flow of blood through the liver. In the early stages of cirrhosis, the liver continues to work. As cirrhosis gets worse, the liver begins to fail.

Liver failure

Also called end-stage liver disease, liver failure progresses over months or years. With end-stage liver disease, the liver can no longer perform important functions or replace damaged cells.

Liver cancer

Having chronic hepatitis B and chronic hepatitis D increases your chance of developing liver cancer. Your doctor may suggest blood tests and an ultrasound or other 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 D?

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

  • feeling tired
  • nausea and vomiting
  • poor appetite
  • pain over the liver, in the upper part of the abdomen
  • darkening of the color of urine
  • lightening of the color of stool
  • yellowish tint to the whites of the eyes and skin, called jaundice

In contrast, most people with chronic hepatitis D have few symptoms until complications develop, which could be several years after they were infected. Some symptoms of cirrhosis include

  • weakness and feeling tired
  • weight loss
  • swelling of the abdomen
  • swelling of the ankles, called edema
  • itching skin
  • jaundice

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 drug needles or other drug materials 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

The hepatitis D virus rarely spreads from mother to child during birth.

You can’t get hepatitis D from

  • being coughed on 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
  • sitting next to an infected person

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 about 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 color
  • swelling in your lower legs, feet, or ankles
  • tenderness or swelling in your abdomen

What tests do doctors use to diagnose hepatitis D?

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

Blood test

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 tests to find out whether you have liver damage or how much liver damage you have—or to rule out other causes of liver disease. These tests may include

  • blood tests.
  • elastography, a special ultrasound that measures the stiffness of your liver.
  • a liver biopsy, in which a doctor uses a needle to take a small piece of tissue from your liver. A pathologist will examine the tissue under a microscope to look for signs of damage or disease.

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

How do doctors treat hepatitis D?

Doctors may treat chronic hepatitis D with medicines called interferons, such as peginterferon alfa-2a (Pegasys). Researchers are studying new treatments for hepatitis D. In addition, medicines for hepatitis B may be needed. These are usually medicines taken once daily by mouth.

How do doctors treat the complications of hepatitis D?

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

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

How can I protect myself from hepatitis D infection?

If you do not 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 do not get hepatitis B, you cannot get hepatitis D.

If you already have hepatitis B, you can take steps to prevent hepatitis D infection by

  • not sharing drug needles or other drug materials
  • wearing gloves if you have to touch another person’s blood or open sores
  • not sharing personal items such as toothbrushes, razors, or nail clippers

How can I prevent spreading hepatitis D to others?

If you have hepatitis D, 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. Preventing hepatitis B will also prevent hepatitis D.

You can 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.

Eating, diet, and nutrition for hepatitis D

If you have hepatitis D, you should eat a balanced, healthy diet. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

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 normal cells in your body. The hepatitis E virus has different types that spread in different ways.

  • Some types are spread by drinking contaminated water. These types are more common in developing countries, including parts of Africa, Asia, Central America, and the Middle East.
  • Other types are spread by eating undercooked pork or wild game, such as deer. These types are more common in developed countries, such as the United States, Australia, Japan, and parts of Europe and East Asia.

Hepatitis E typically causes acute, or short-term, infection.

Acute hepatitis E

Acute hepatitis E is a short-term infection. In most cases, people’s bodies are able to recover and fight off the infection and the virus goes away. People usually get better without treatment after several weeks.

Chronic hepatitis E

Chronic hepatitis E is a long-lasting infection that occurs when your body isn’t able to fight off the virus and the virus does not go away. Chronic hepatitis E is rare and only occurs in people with weakened immune systems. For example, hepatitis E may become chronic in people taking medicines that weaken their immune system after an organ transplant, or in people who have HIV or AIDS.

How common is hepatitis E?

Hepatitis E is more common in developing countries, where sanitation is poor and access to clean water is limited.

Although experts used to think hepatitis E was rare in the United States, recent research suggests that about 20 percent of the population has had hepatitis E.25

How serious is hepatitis E?

The types of hepatitis E that are common in developing countries are likely to cause severe infections, especially in pregnant women.

The types of hepatitis E that are common in developed countries are often mild and cause no symptoms. Many people don’t know they’ve had these types of hepatitis E.

Who is more likely to get hepatitis E?

Different types of hepatitis E are more likely to affect different groups of people. The types of hepatitis E that are more common in developing countries are more likely to affect adolescents and young adults.26

In contrast, the types of hepatitis E that are more common in developed countries most often affect older men.26

What are the complications of hepatitis E?

Acute hepatitis E complications

Most people recover from acute hepatitis E without complications. In some cases, acute hepatitis E may cause acute liver failure, a condition in which the liver fails suddenly. Acute liver failure due to hepatitis E is more common in

  • pregnant women
  • people who have other liver diseases

In pregnant women, hepatitis E can cause other complications for the mother and baby, such as stillbirth, premature birth, or low birthweight.

Chronic hepatitis E complications

Chronic hepatitis E—which is rare and only occurs in people with weakened immune systems—may lead to complications such as cirrhosis or liver failure.

What are the symptoms of hepatitis E?

Many people infected with hepatitis E have no symptoms. Some people have symptoms 15 to 60 days after they become infected with the virus.27 These symptoms may include

  • feeling tired
  • nausea and vomiting
  • poor appetite
  • pain over the liver, in the upper part of the abdomen
  • darkening of the color of urine
  • lightening of color of stool
  • yellowish tint to the whites of 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 developing countries, hepatitis E typically spreads through drinking contaminated water. In developed countries, such as the United States, hepatitis E typically spreads from animals to people, when people eat undercooked pork or wild game, such as deer.

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

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 hepatitis E. The virus can also be detected in blood and in stool samples taken during acute hepatitis E infection.

How do doctors treat hepatitis E?

Treatment for acute hepatitis E includes resting, drinking plenty of liquids, and eating healthy foods to help relieve symptoms.

Talk with your doctor before taking any prescription or over-the-counter medicines, vitamins or other dietary supplements, or complementary or alternative medicines—any of these could damage your liver. You should avoid alcohol until your doctor tells you that you have completely recovered from hepatitis E.

See your doctor regularly to make sure your body has fully recovered.

Doctors may treat chronic hepatitis E with ribavirin or peginterferon alfa-2a (Pegasys).

How can I protect myself from hepatitis E infection?

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

Also, make sure any pork or deer you eat is thoroughly cooked, both in developing countries and in developed countries such as the United States.

A person choosing bottled water at a store
When traveling in a developing country, drink bottled water.

How can I prevent spreading hepatitis E to others?

Research suggests that it is 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 warm, soapy water after using the toilet and before preparing food. Talk with a blood donation center before you donate blood.

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.

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

If you have hepatitis E, you should eat a balanced, healthy diet. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

References

May 2017
Share

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. The 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 the NIDDK is carefully reviewed by NIDDK scientists and other experts.

The NIDDK would like to thank:
Raymond Chung, M.D., Massachusetts General Hospital; Adrian M. Di Bisceglie, M.D., Saint Louis University School of Medicine; Paul Martin, M.D., University of Miami Miller School of Medicine