Hepatitis B

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is hepatitis B?

Hepatitis B is a serious viral liver infection. The term ‘hepatitis’ means inflammation of the liver. It is a form of liver disease. The hepatitis B virus infects the liver, which causes harmful inflammation and impairs liver function. The liver is an essential organ required for hundreds of functions, such as removing waste products from the blood, controlling cholesterol production, and making clotting factors, immune substances, and bile. In the United States, sexual contact is the most common route of transmission for hepatitis B. A hepatitis B vaccine is available to prevent the infection if you are at risk, such as having multiple sex partners.

Hepatitis B passes from person to person in blood, semen, and other bodily fluids. It starts as an acute infection that may or may not cause symptoms in adults. Most adults—95%—will clear the virus and recover fully from the acute phase. Some will go on to develop a chronic infection. Nearly all babies who get hepatitis B during birth will also develop a chronic infection.

After exposure to the virus, it can take about 90 days to develop symptoms. About one-third of adults experience noticeable symptoms. When adults have symptoms, they usually resemble flu symptoms. This can include fever, fatigue, joint pain, and appetite loss. Yellowing of the skin and eyes can also occur. About two-thirds of infected individuals do not have symptoms and rarely know they are sick. Unfortunately, you can pass the virus to others even if you don’t have symptoms.

Doctors generally do not treat acute hepatitis B with medications; rest is usually sufficient to help your body fight the infection. If the infection becomes chronic, doctors treat it with antiviral medicines and interferons. Chronic hepatitis B treatment is typically lifelong. See your doctor promptly if you have symptoms of hepatitis B. Seek immediate medical care if you think you have been exposed to hepatitis B. It may be possible to prevent the infection if you receive the vaccine and HBIG shot within 12-24 hours of exposure. HBIG is hepatitis B immune globulin, which contains antibodies against hepatitis B.

What are the symptoms of hepatitis B?

Symptoms of acute hepatitis B occur in about one-third or more of infected adults and children older than 5 years. Symptoms can start as soon as two weeks after exposure or up to five months later. Symptoms also can last for a few weeks to a few months. Most people recover from this acute infection.

Children younger than 5 years and immunosuppressed adults tend not to show symptoms of hepatitis B infection.

Common symptoms of hepatitis B

Hepatitis B causes the following common symptoms:

An acute hepatitis B infection can progress to a chronic infection. Similar to acute hepatitis B, some people experience symptoms of chronic hepatitis B, but most do not. In some cases, people do not realize they were chronically infected until they develop signs and symptoms of liver disease and liver failure.

Serious symptoms that might indicate a life-threatening condition

In rare cases, hepatitis B can be life threatening and cause acute liver failure. This condition is called fulminant hepatitis. It is a medical emergency and can cause serious bleeding and pressure in the brain. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

See your doctor if you have any hepatitis B symptoms. A blood test is the only way to know if you have hepatitis B or not. Knowing your status is important. You can pass the infection to other people even if you don’t have symptoms. Blood work also is necessary to determine if the infection has become chronic.

What causes hepatitis B?

Hepatitis B is a contagious viral infection. Sexual transmission is the main way it spreads in the United States. You can get it through contact with infected blood, semen, or vaginal secretions. You can also get it by sharing needles with an infected person or through an accidental needle stick. Pregnant women who have hepatitis B can pass it to their babies during birth as well.

About 5% of hepatitis B infections in adults become chronic, lifelong infections. Most infants (about 90%) who contract hepatitis B will develop a chronic infection. The rate of chronic hepatitis B is 25 to 50% in infected children younger than 5 years.

What are the risk factors for hepatitis B?

People at risk of contracting hepatitis B infection include: 

  • Babies born to infected mothers

  • Healthcare providers who are exposed to blood

  • Men who have sex with men

  • People who share needles for injectable drugs

  • People who have other STDs (sexually transmitted diseases)

  • People who have unprotected sex or multiple sex partners

  • People who live with or have sex with someone with hepatitis B

Reducing your risk of hepatitis B

Fortunately, hepatitis B infection is preventable. Like other STDs, it only takes one act of unprotected sex with an infected person to become infected. You can lower your risk of hepatitis B by:

  • Getting the full hepatitis B vaccine series, which involves 3 to 4 injections over six months

  • Knowing your sex partner’s hepatitis B status

  • Not using injection drugs and not sharing needles

  • Practicing safe sex, including using a new latex or polyurethane condom every time you have sexual contact or come in contact with semen or vaginal secretions

  • Researching tattoo or piercing shops to make sure they use sterile equipment

  • Wearing gloves when giving first aid or cleaning up or coming in contact with blood

Seek immediate medical care if you may have had an exposure to hepatitis B. Treating the exposure within 12 to 24 hours may prevent the infection. Post-exposure treatment includes the vaccine and possibly HBIG (hepatitis B immune globulin). HBIG contains antibodies against hepatitis B.

How is hepatitis B treated?

If you have symptoms of hepatitis B infection and seek a medical diagnosis and treatment, your doctor will check your liver function with blood tests. He or she likely won’t prescribe any medicines. Instead, doctors typically recommend supportive measures. This includes drinking plenty of fluids, resting, and eating a balanced diet to support your health and nutrition. Medicines, and even hospitalization, may be necessary for severe symptoms. About 95% of adults will clear the acute infection, just like many other viral infections.

If hepatitis B infection becomes chronic, you may or may not need to start treatment right away. In general, treatment is most effective when there are signs of active liver disease. So, your doctor may monitor your liver to decide when it is time to start treatment.

Chronic hepatitis B treatment includes two categories of medicines. The first is antiviral medicine. These drugs slow or stop viral reproduction, which helps prevent liver damage. Antivirals will not cure hepatitis B and they will only work as long as you are taking them. Because of this, you typically need to take these medicines for life.

First-line antiviral medicines for hepatitis B include:

  • Entecavir (Baraclude)

  • Tenofovir alafenamide (Vemlidy)

  • Tenofovir disoproxil (Viread)

Second-line antiviral medicines for hepatitis B include:

  • Adefovir dipivoxil (Hepsera)

  • Lamivudine (Epivir-HBV, Heptodin, Zeffix)

  • Telbivudine (Sebivo, Tyzeka)

The other type of hepatitis B medicine is interferon. Interferons are immune stimulators that help your body fight infection. Interferon drugs for hepatitis B include:

  • Pegylated interferon (Pegasys), which is a weekly injection and a first-line treatment

  • Interferon alpha (Intron A), which is an older product that is not a preferred treatment

Interferons can be difficult to take due to side effects. They are generally not the first choice for hepatitis B treatment. They can be useful when people are not ready for long-term treatment.

What are the potential complications of hepatitis B?

Chronic hepatitis B can lead to serious complications. Ongoing inflammation in the liver can cause cirrhosis, which is scarring in the liver. This condition prevents the liver from functioning normally. If the damage continues, end-stage liver disease and failure can occur. A liver transplant is the only effective treatment for liver failure. People with hepatitis B are also at risk of developing liver cancer. About 15% of adults with chronic hepatitis B will die from the disease.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jul 13
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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