Question: What is hepatitis D?
Answer: 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
Question: How do hepatitis D and hepatitis B infections occur together?
Answer: 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
Question: How common is hepatitis D?
Answer: 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
Question: Who is more likely to get hepatitis D?
Answer: People are more likely to get hepatitis D if they

are already infected with hepatitis B
haveHIV
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 anarea of the world where hepatitis D is more common
have multiple sex partners or a history of sexually transmitted disease
Question: What are the complications of hepatitis D?
Answer: 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 anultrasoundor another type of imaging test to check for liver cancer. Finding cancer at an early stage improves the chances of curing the cancer.
Question: What are the symptoms of hepatitis D?
Answer: Most people with acute hepatitis D have symptoms, which may include

darkerurinecolor and lighterstoolcolor
fatigue, or feeling tired
fever
joint pain
loss of appetite,nausea, orvomiting
pain in theabdomen
yellow tint to the eyes and skin, calledjaundice

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
Question: What causes hepatitis D?
Answer: 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.
Question: How do doctors diagnose hepatitis D?
Answer: 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.

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.
ultrasoundor 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.
Question: How do doctors treat hepatitis D?
Answer: 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.
Question: How do doctors treat the complications of hepatitis D?
Answer: 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.
Question: How can I protect myself from hepatitis D infection?
Answer: 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
Question: How can I prevent spreading hepatitis D to others?
Answer: 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.
Question: Is a hepatitis D vaccine available?
Answer: No vaccine for hepatitis D is currently available. The hepatitis B vaccine can prevent hepatitis D by preventing hepatitis B.
Question: What should I eat and drink if I have hepatitis D?
Answer: 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.
Question: Clinical Trials for Hepatitis D
Answer: NIDDK conducts and supports clinical trials in many diseases and conditions, including liver diseases. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.

What are clinical trials for hepatitis 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.