Hepatitis B is a serious liver infection caused by the hepatitis B virus (HBV). For most people, hepatitis B is short term, also called acute. Acute hepatitis B lasts less than six months. But for others, the infection lasts more than six months and is called chronic. Chronic hepatitis B raises the risk of liver failure, liver cancer and serious scarring of the liver called cirrhosis.

Most adults with hepatitis B recover fully, even if their symptoms are bad. Infants and children are more likely to develop a chronic, long-lasting hepatitis B virus infection.

A vaccine can prevent infection with the hepatitis B virus. For those who get infected, treatment depends on whether the infection is acute or chronic. Some people need medicine. Others with serious liver damage from a chronic infection need a liver transplant. If you're infected, taking certain safety measures can help prevent spreading the virus to others.

Symptoms of acute hepatitis B range from mild to serious. The symptoms usually start about 1 to 4 months after you've been infected with HBV. But you could notice them as early as two weeks after you're infected. Some people with acute or chronic hepatitis B may not have any symptoms, especially young children.

Hepatitis B symptoms may include:

• Pain in the stomach area, also called the abdomen.
• Dark urine.
• Fever.
• Joint pain.
• Loss of appetite.
• Upset stomach and vomiting.
• Weakness and extreme tiredness.
• Jaundice, which is a yellowing of the whites of the eyes and the skin. Depending on skin color, this change may be harder or easier to see.

When to see a doctor

If you know you've been exposed to the hepatitis B virus, call your healthcare professional right away. A preventive treatment may lower your risk of infection if you get the treatment within 24 hours of exposure to the virus.

If you think you have symptoms of hepatitis B, call your healthcare professional.

Hepatitis B is caused by the hepatitis B virus (HBV). The virus passes from person to person through blood, semen or other body fluids. It does not spread by sneezing or coughing.

Common ways that HBV can spread are:

• Sexual contact. You may get hepatitis B if you have sex with someone who is infected and you don't use a condom. The virus can pass to you if the person's blood, saliva, semen or vaginal fluids enter your body.
• Sharing of needles. HBV easily spreads through needles and syringes that are tainted with infected blood. Sharing equipment used to inject illicit drugs puts you at high risk of hepatitis B.
• Accidental needlesticks. Hepatitis B is a concern for healthcare workers and anyone else who comes in contact with human blood.
• Pregnant person to newborn. Pregnant people infected with HBV can pass the virus to their babies during childbirth. But the newborn can be vaccinated to prevent getting infected in almost all cases. Talk with your healthcare professional about being tested for hepatitis B if you are pregnant or want to become pregnant.

Acute versus chronic hepatitis B

HBV infection may be short-lived, also called acute. Or it might last a long time, also known as chronic.

• Acute HBV infection lasts less than six months. Your immune system likely can clear the hepatitis B virus from your body. You should recover fully within a few months. Most people who get HBV infections as adults have an acute infections. But these can lead to a chronic infections.
• Chronic HBV infection lasts six months or longer. It lingers because the immune system can't fight off the infection. Chronic hepatitis B virus infection may last a lifetime. It can lead to serious illnesses such as cirrhosis and liver cancer. Some people with chronic hepatitis B may have no symptoms at all. Some may have ongoing tiredness and mild symptoms of acute hepatitis.

The younger you are when you get hepatitis B, the higher your risk of the condition becoming chronic. That's especially true for newborns or children younger than 5. Chronic hepatitis B may not be detected for decades until a person becomes very ill from liver disease.

The hepatitis B virus spreads through contact with blood, semen or other body fluids from an infected person. Your risk of HBV infection rises if you:

• Have sex without a condom with multiple sex partners or with someone who's infected with HBV.
• Share needles during the use of drugs injected into a vein.
• Are born male and have sex with men.
• Live with someone who has a chronic HBV infection.
• Are an infant who was born to an infected pregnant person.
• Have a job that exposes you to human blood.
• Have hepatitis C or HIV.
• Receive dialysis treatment.
• Are or have been in prison.
• Need to take medicine that can weaken the immune system, such as chemotherapy.
• Travel to regions with high infection rates of HBV, such as Asia, the Pacific Islands, Africa and Eastern Europe.

Having a chronic HBV infection can lead to serious health conditions called complications. These include:

• Scarring of the liver, also called cirrhosis. Swelling called inflammation is linked with hepatitis B. The inflammation can lead to cirrhosis that may prevent the liver from working as it should.
• Liver cancer. People with chronic hepatitis B have a higher risk of liver cancer.
• Liver failure. Acute liver failure is a condition in which the vital functions of the liver shut down. When that happens, a liver transplant is needed to stay alive.

• Sudden increase in the level of hepatitis B virus. In some people with chronic hepatitis B, levels of the virus are low or haven't yet been found by tests. If the virus starts to quickly make copies of itself, tests may spot this rise or find the virus. This is called reactivation of the virus. It can lead to liver damage or even liver failure.

  Reactivation tends to affect people who have weakened immune systems, also called suppressed immune systems. This includes people on medicines that weakens the immune system, such as high-dose corticosteroids or chemotherapy. Before taking these medicines, you should be tested for hepatitis B. If testing shows that you have hepatitis B, see a liver specialist called a hepatologist before you start these medicines.

• Other conditions. People with chronic hepatitis B may develop kidney disease or inflammation of blood vessels.

The hepatitis B vaccine is the main way to prevent infection with HBV. The vaccine is given as two shots one month apart, or three or four shots over six months. How many shots you get depends on the type of hepatitis B vaccine that you're given. You can't get hepatitis B from the vaccine.

In the United States, the Advisory Committee on Immunization Practices recommends vaccination at birth for infants born to someone who has either tested positive for the virus or has an infection status that is not known.

For pregnant people who don't have hepatitis B, the committee recommends that they and their healthcare professionals decide together when to start the hepatitis B shots for their babies. If babies don't get the dose at birth, they should not receive the first shot until they are at least 2 months old.

The committee also states that parents and health professionals can consider checking the baby's antibody levels later to see if more shots are needed.

If you didn't get vaccinated as a baby or child, the committee still recommends the vaccine for everyone through age 59. If you're age 60 or older and haven't gotten vaccinated, get the vaccine if you're at risk of being exposed to the hepatitis B virus. People 60 and over who haven't been vaccinated and are not at high risk also can choose to get the vaccine.

The hepatitis B vaccine is strongly recommended for:

• Newborns.
• Children and adolescents not vaccinated at birth.
• Those who work or live in centers for people who have developmental disabilities.
• People who live with someone who has hepatitis B.
• Healthcare workers, emergency workers and other people who come into contact with blood.
• Anyone who has a sexually transmitted infection, including HIV.
• People born male who have sex with men.
• People who have multiple sexual partners.
• Sexual partners of someone who has hepatitis B.
• People who inject street drugs or share needles and syringes.
• People with chronic liver disease.
• People with end-stage kidney disease.
• Travelers planning to go to an area of the world with a high HBV infection rate.

Take safety measures to help prevent HBV infection

Other ways to lower your risk of infection with the hepatitis B virus include:

• Know the HBV status of any sexual partner. Don't have sex without a condom unless you know that your partner doesn't have hepatitis B or another sexually transmitted infection.
• Use a new latex or polyurethane condom every time you have sex if you don't know the health status of your partner. Condoms can lower your risk of catching HBV, but they don't get rid of the risk completely.
• Don't use street drugs. If you use drugs, get help to stop. If you can't stop, use a sterile needle each time you inject drugs. Never share needles.
• Be cautious about body piercing and tattooing. If you want to get a piercing or tattoo, look for a reputable shop. Ask about how the equipment is cleaned. Make sure the employees use sterile needles. If you can't get answers, look for another shop.
• Ask about the hepatitis B vaccine before you travel. If you're traveling to a region where hepatitis B is common, ask your healthcare professional about the hepatitis B vaccine in advance. It's usually given in a series of three shots over a six-month period.

Diagnosis involves the steps that your healthcare professional takes to find out if you have hepatitis B. Your healthcare professional gives you a physical exam and looks for symptoms of liver damage. These symptoms can include yellowing skin and stomach pain. Tests that can help diagnose hepatitis B or its complications are:

• Blood tests. Blood tests can detect the hepatitis B virus in your body. They also can tell your healthcare professional if the infection is acute or chronic. A simple blood test also can find out if you're immune to the condition.
• Liver ultrasound. A special ultrasound called transient elastography can show the amount of liver damage.
• Liver biopsy. Your healthcare professional might remove a small sample of your liver for testing to check for liver damage. This is called a liver biopsy. During this test, your healthcare professional inserts a thin needle through your skin and into your liver. The needle removes a tissue sample for the lab to check.

Screening healthy people for hepatitis B

Healthcare professionals sometimes test certain healthy people for hepatitis B. This is called screening. Screening is done because HBV can damage the liver before the infection causes symptoms. Talk with your healthcare professional about screening for hepatitis B if you:

• Are pregnant.
• Live with someone who has hepatitis B.
• Have had many sexual partners.
• Have had sex with someone who has hepatitis B.
• Were born male and have sex with men.
• Have a history of a sexually transmitted infection.
• Have HIV or hepatitis C.
• Have a liver enzyme test with irregular results that can't be explained.
• Receive kidney dialysis.
• Take medicines that suppress the immune system, such as those used to prevent rejection after an organ transplant.
• Use injected street drugs.
• Are in prison.
• Were born in a country where hepatitis B is common, including Asia, the Pacific Islands, Africa and Eastern Europe.
• Have parents or adopted children from places where hepatitis B is common, including Asia, the Pacific Islands, Africa and Eastern Europe.

Treatment to prevent HBV infection after exposure

If you know you've been exposed to the hepatitis B virus, call a healthcare professional right away. It's important to know if you've been vaccinated for hepatitis B. A healthcare professional asks you when you were exposed and what kind of exposure you had.

Medicine called immunoglobulin may help protect you from getting sick with hepatitis B. You need to receive a shot of the medicine within 24 hours of exposure to the hepatitis B virus. This treatment only provides short-term protection. So you also should get the hepatitis B vaccine at the same time if you never received it.

Treatment for acute HBV infection

You might not need treatment for an acute hepatitis B virus infection. The infection is short lived and most often it goes away on its own. A healthcare professional might recommend:

• Rest.
• Proper nutrition.
• Plenty of fluids.
• Close monitoring while your body fights the infection.

If your symptoms are severe, you may need antiviral medicines or a hospital stay to prevent complications.

Treatment for chronic HBV infection

Most people with chronic hepatitis B virus infection need treatment for the rest of their lives. The decision to start treatment depends on many factors, including whether:

• The virus is causing inflammation or scarring of the liver, also called cirrhosis.
• You have other infections, such as hepatitis C or HIV.
• Your immune system is weakened by medicine or illness.

Treatment helps lower the risk of liver disease and prevents you from passing the infection to others.

Treatment for chronic hepatitis B may include:

• Antiviral medicines. Many antiviral medicines can help fight the virus and slow its ability to damage your liver. These medicines include entecavir (Baraclude), tenofovir (Viread), lamivudine (Epivir) and adefovir (Hepsera). You take them by mouth, most often for the long term. Your healthcare professional may recommend combining two of these medicines. Or the healthcare professional may have you take one of these medicines with interferon to improve treatment response.

• Interferon shots. Interferon is a lab-made version of a substance that the body makes to fight infection. This type of medicine includes peginterferon alfa-2a (Pegasys). One upside of interferon shots is that they're taken for a much shorter time than are oral antiviral medicines. But interferon has a high rate of side effects, such as upset stomach, vomiting, trouble breathing and depression.

  Interferon mainly is used for young people with hepatitis B who wish to not need long-term treatment. It's also used for women who might want to get pregnant within a few years. Women should use birth control during interferon treatment. Do not take interferon during pregnancy. Interferon also is not right for people with cirrhosis or acute liver failure.

• Liver transplant. If your liver has been badly damaged, a liver transplant may be an option. During a liver transplant, the surgeon removes your damaged liver and replaces it with a healthy liver. Most transplanted livers come from deceased donors. A small number come from living donors who donate a part of their livers.

Other medicines to treat hepatitis B are being developed.

If you've been infected with the hepatitis B virus, take steps to protect others.

• Make sex safer. If you're sexually active, tell your partner you have HBV. Talk about the risk of your partner catching the virus from you. Use a new latex condom every time you have sex. Be aware that condoms lower the risk but don't get rid of the risk completely.
• Tell your sexual partner to get tested. Anyone with whom you've had sex needs to be tested for the virus. Your partners also need to know their HBV status so that they don't infect others. If tests show that they've been infected, they should get healthcare checkups to see if they need treatment.
• Don't share personal care items. If you use injected drugs, never share needles and syringes. And don't share razor blades or toothbrushes, because they may carry traces of infected blood.

If you have hepatitis B, the following tips might help you cope:

• Learn about hepatitis B. The Centers for Disease Control and Prevention is a good place to start.
• Stay connected to friends and family. You can't spread hepatitis B through casual contact, so don't cut yourself off from people who can offer support.
• Take care of yourself. Eat a healthy diet full of fruits and vegetables, exercise regularly, and get enough sleep.
• Take care of your liver. Don't drink alcohol or take new medicines without talking with your healthcare professional first. Get tested for hepatitis A and C. Get vaccinated for hepatitis A if you haven't been exposed.

You're likely to start by seeing your family healthcare professional. You may be referred to a specialist right away. Doctors who specialize in treating hepatitis B include:

• Doctors called gastroenterologists, who treat digestive diseases.
• Doctors called hepatologists, who treat liver diseases.
• Doctors who treat infectious diseases.

What you can do

Here's some information to help you get ready for your appointment.

• Be aware of any restrictions before your healthcare checkup. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
• Write down your symptoms, including any that may not seem related to the reason for which you made the appointment.
• Write down key personal information, including major stresses or recent life changes.
• Make a list of all medicines, vitamins and supplements you take. Include the doses.
• Take a family member or friend along if you can. Someone who joins you may help you remember the information that your healthcare team gives you.
• Write down questions to ask your healthcare professional.

For hepatitis B, some basic questions to ask include:

• What is likely causing my symptoms or condition?
• Other than the most likely cause, what are other possible causes for my symptoms or condition?
• What tests do I need?
• Is my condition likely short- or long-term?
• Has hepatitis B damaged my liver or caused other complications, such as kidney conditions?
• What is the best course of action?
• Are there other treatment choices aside from the main treatment that you've suggested?
• I have other health conditions. How can I best manage them together?
• Are there restrictions that I need to follow?
• Should I see a specialist?
• Should my family be tested for hepatitis B?
• How can I protect people around me from HBV?
• Is there a generic version of the medicine you're prescribing?
• Are there brochures or other printed material I can have? What websites do you recommend?

What to expect from your doctor

Your healthcare professional is likely to ask you questions such as:

• When did your symptoms start?
• Have you ever had jaundice symptoms, including yellowing of the eyes or clay-colored stool?
• Have you been vaccinated for hepatitis B?
• Do your symptoms happen all the time or once in a while?
• How bad are your symptoms?
• What, if anything, seems to make your symptoms better?
• What, if anything, appears to make your symptoms worse?
• Have you ever had a blood transfusion?
• Do you inject drugs?
• Have you had sex without a condom?
• How many sexual partners have you had?
• Have you been diagnosed with hepatitis?