Overview

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

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.

Causes

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.

Risk factors

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.

Complications

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.

Prevention

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 that infants get their first shot of the vaccine after they're born. 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.
By Mayo Clinic Staff