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, and lasts less than six months. But for others, the infection becomes chronic, meaning it lasts more than six months. Having chronic hepatitis B increases your risk of developing liver failure, liver cancer or cirrhosis — a condition that permanently scars the liver.

Most adults with hepatitis B recover fully, even if their symptoms are severe. Infants and children are more likely to develop a long-lasting hepatitis B infection. This is known as a chronic infection.

A vaccine can prevent hepatitis B, but there's no cure if you have the condition. If you're infected, taking certain precautions can help prevent spreading the virus to others.

Symptoms of acute hepatitis B range from mild to severe. They usually appear about 1 to 4 months after you've been infected, although you could see them as early as two weeks after you're infected. Some people, usually young children, may not have any symptoms.

Hepatitis B signs and symptoms may include:

• Abdominal pain
• Dark urine
• Fever
• Joint pain
• Loss of appetite
• Nausea and vomiting
• Weakness and fatigue
• Yellowing of the skin and the whites of the eyes, also called jaundice

When to see a doctor

If you know you've been exposed to hepatitis B, contact your health care provider immediately. A preventive treatment may reduce your risk of infection if you receive the treatment within 24 hours of exposure to the virus.

If you think you have symptoms of hepatitis B, contact your health care provider.

Hepatitis B infection is caused by the hepatitis B virus (HBV). The virus is passed 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 unprotected sex with someone who is infected. The virus can pass to you if the person's blood, saliva, semen or vaginal secretions enter your body.
• Sharing of needles. HBV easily spreads through needles and syringes contaminated with infected blood. Sharing IV drug paraphernalia puts you at high risk of hepatitis B.
• Accidental needle sticks. Hepatitis B is a concern for health care workers and anyone else who comes in contact with human blood.
• Mother to child. Pregnant women infected with HBV can pass the virus to their babies during childbirth. However, the newborn can be vaccinated to avoid getting infected in almost all cases. Talk to your provider about being tested for hepatitis B if you are pregnant or want to become pregnant.

Acute vs. chronic hepatitis B

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

• Acute hepatitis B infection lasts less than six months. Your immune system likely can clear acute hepatitis B from your body, and you should recover completely within a few months. Most people who get hepatitis B as adults have an acute infection, but it can lead to chronic infection.
• Chronic hepatitis B infection lasts six months or longer. It lingers because your immune system can't fight off the infection. Chronic hepatitis B infection may last a lifetime, possibly leading 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 fatigue and mild symptoms of acute hepatitis.

The younger you are when you get hepatitis B — particularly newborns or children younger than 5 — the higher your risk of the infection becoming chronic. Chronic infection may go undetected for decades until a person becomes seriously ill from liver disease.

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

• Have unprotected sex with multiple sex partners or with someone who's infected with HBV
• Share needles during IV drug use
• Are a man who has sex with other men
• Live with someone who has a chronic HBV infection
• Are an infant born to an infected mother
• Have a job that exposes you to human blood
• 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 complications, such as:

• Scarring of the liver (cirrhosis). The inflammation associated with a hepatitis B infection can lead to extensive liver scarring (cirrhosis), which may impair the liver's ability to function.
• Liver cancer. People with chronic hepatitis B infection have an increased risk of liver cancer.
• Liver failure. Acute liver failure is a condition in which the vital functions of the liver shut down. When that occurs, a liver transplant is necessary to stay alive.
• Reactivation of the hepatitis B virus. People with chronic hepatitis B who have suppression of their immune system are prone to reactivation of the hepatitis B virus. This can lead to significant liver damage or even liver failure. This includes people on immunosuppressive medications, such as high-dose corticosteroids or chemotherapy. Before taking these medications, you should be tested for hepatitis B. If you test positive for hepatitis B, you should be seen by a liver specialist (hepatologist) before starting these therapies.
• Other conditions. People with chronic hepatitis B may develop kidney disease or inflammation of blood vessels.

The hepatitis B vaccine is typically given as two injections separated by a month or three or four injections over six months, depending on which vaccine is given. You can't get hepatitis B from the vaccine. The hepatitis B vaccine is recommended by the United States Advisory Committee on Immunization Practices for adults 19 to 59 years of age who do not have a contraindication to the vaccine.

The hepatitis B vaccine is also strongly recommended for:

• Newborns
• Children and adolescents not vaccinated at birth
• Those who work or live in a center for people who are developmentally disabled
• People who live with someone who has hepatitis B
• Health care workers, emergency workers and other people who come into contact with blood
• Anyone who has a sexually transmitted infection, including HIV
• Men who have sex with men
• People who have multiple sexual partners
• Sexual partners of someone who has hepatitis B
• People who inject illegal 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 hepatitis B infection rate

Take precautions to avoid HBV

Other ways to reduce your risk of HBV include:

• Know the HBV status of any sexual partner. Don't engage in unprotected sex unless you're absolutely certain your partner isn't infected with HBV or any other 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. Remember that although condoms can reduce your risk of contracting HBV, they don't eliminate the risk.
• Don't use illegal drugs. If you use illicit drugs, get help to stop. If you can't stop, use a sterile needle each time you inject illicit drugs. Never share needles.
• Be cautious about body piercing and tattooing. If you 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 provider about the hepatitis B vaccine in advance. It's usually given in a series of three injections over a six-month period.

Your health care provider will examine you and look for signs of liver damage, such as yellowing skin or belly pain. Tests that can help diagnose hepatitis B or its complications are:

• Blood tests. Blood tests can detect signs of the hepatitis B virus in your body and tell your provider whether it's acute or chronic. A simple blood test can also determine 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 provider 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 provider inserts a thin needle through your skin and into your liver and removes a tissue sample for laboratory analysis.

Screening healthy people for hepatitis B

Health care providers sometimes test certain healthy people for hepatitis B infection because the virus can damage the liver before causing signs and symptoms. Talk to your provider about screening for hepatitis B infection 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
• Are a man who has sex with men
• Have a history of a sexually transmitted illness
• Have HIV or hepatitis C
• Have a liver enzyme test with unexplained abnormal results
• Receive kidney dialysis
• Take medications that suppress the immune system, such as those used to prevent rejection after an organ transplant
• Use illegal injected 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 hepatitis B infection after exposure

If you know you've been exposed to the hepatitis B virus, call your health care provider immediately. It is important to know whether you have been vaccinated for hepatitis B. Your health care provider will want to know when you were exposed and what kind of exposure you had.

An injection of immunoglobulin (an antibody) given within 24 hours of exposure to the virus may help protect you from getting sick with hepatitis B. Because this treatment only provides short-term protection, you also should get the hepatitis B vaccine at the same time if you never received it.

Treatment for acute hepatitis B infection

If your provider determines your hepatitis B infection is acute — meaning it is short lived and will go away on its own — you may not need treatment. Instead, your provider might recommend rest, proper nutrition, plenty of fluids and close monitoring while your body fights the infection. In severe cases, antiviral drugs or a hospital stay is needed to prevent complications.

Treatment for chronic hepatitis B infection

Most people diagnosed with chronic hepatitis B infection need treatment for the rest of their lives. The decision to start treatment depends on many factors, including: if the virus is causing inflammation or scarring of the liver, also called cirrhosis; if you have other infections, such as hepatitis C or HIV; or if your immune system is suppressed by medicine or illness. Treatment helps reduce the risk of liver disease and prevents you from passing the infection to others.

Treatment for chronic hepatitis B may include:

• Antiviral medications. Several antiviral medicines — including entecavir (Baraclude), tenofovir (Viread), lamivudine (Epivir), adefovir (Hepsera) and telbivudine — can help fight the virus and slow its ability to damage your liver. These drugs are taken by mouth. Your provider may recommend combining two of these medications or taking one of these medications with interferon to improve treatment response.
• Interferon injections. Interferon alfa-2b (Intron A) is a man-made version of a substance produced by the body to fight infection. It's used mainly for young people with hepatitis B who wish to avoid long-term treatment or women who might want to get pregnant within a few years, after completing a finite course of therapy. Women should use contraception during interferon treatment. Interferon should not be used during pregnancy. Side effects may include nausea, vomiting, difficulty breathing and depression.
• Liver transplant. If your liver has been severely 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, though a small number come from living donors who donate a portion of their livers.

Other drugs to treat hepatitis B are being developed.

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

• Make sex safer. If you're sexually active, tell your partner you have HBV and talk about the risk of transmitting it to him or her. Use a new latex condom every time you have sex, but remember that condoms reduce but don't eliminate the risk.
• 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 positive, they should be evaluated for possible treatment.
• Don't share personal care items. If you use IV drugs, never share needles and syringes. And don't share razor blades or toothbrushes, which may carry traces of infected blood.

If you've been diagnosed with hepatitis B infection, the following suggestions 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 prescription or over-the-counter drugs without consulting your health care provider. 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 health care provider. However, in some cases, you may be referred immediately to a specialist. Doctors who specialize in treating hepatitis B include:

• Doctors who treat digestive diseases (gastroenterologists)
• Doctors who treat liver diseases (hepatologists)
• Doctors who treat infectious diseases

What you can do

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

• Be aware of pre-appointment restrictions. 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 seem unrelated to the reason for which you scheduled the appointment.
• Write down key personal information, including major stresses or recent life changes.
• Make a list of all medications, vitamins and supplements you take.
• Consider taking a family member or friend along. Someone who accompanies you may help you remember the information you receive.
• Write down questions to ask your provider.

For hepatitis B infection, 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 temporary or chronic?
• Has hepatitis B damaged my liver or caused other complications, such as kidney problems?
• What is the best course of action?
• What are the alternatives to the primary approach you're suggesting?
• 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 prevent people around me from hepatitis B?
• Is there a generic alternative to 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 health care provider is likely to ask you a number of questions, including:

• When did your symptoms begin?
• Have you ever developed jaundice symptoms, including yellowing of the eyes or clay-colored stool?
• Were you previously vaccinated for hepatitis B?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?
• Have you ever had a blood transfusion?
• Do you inject drugs?
• Have you had unprotected sex?
• How many sexual partners have you had?
• Have you been diagnosed with hepatitis?