Hepatitis B is a contagious liver infection caused by the hepatitis B virus. It can be a mild illness lasting a few weeks or it can be a serious and lifelong illness. Hepatitis B virus is spread from person to person by direct contact with infected blood or other bodily fluids.
There are two types of hepatitis B caused by the hepatitis B virus:
- Acute hepatitis B is a short-term illness that occurs within the first 6 months after exposure to the hepatitis B virus. Most adults recover from an acute infection and develop immunity against future infection.
- Chronic hepatitis B is a lifelong infection with the hepatitis B virus. Over time, chronic hepatitis B can cause serious health problems, including liver damage, cirrhosis, liver cancer, and even death.
The younger a person is when infected with hepatitis B virus, the greater the chance of developing a chronic infection. Nine out of ten infants who get infected will develop lifelong (chronic) hepatitis B. Of those, one in four will die of liver problems, such as liver cancer, later in life. Up to half of children infected between one and five years of age will have lifelong infection.
Up to half of people age 5 years and older develop symptoms from acute hepatitis B infection. Other people who have acute hepatitis B, especially kids under five years old and those with a weakened immune system, do not have symptoms. In a small number of acute hepatitis B infections, the person dies very quickly.
If symptoms occur, they can appear anywhere from 8 weeks to 5 months after exposure. Symptoms usually last several weeks, but some people can be acutely sick for as long as 6 months.
The symptoms of acute hepatitis B include:
- Lack of energy
- Low appetite
- Stomach pain
- Joint pain
- Dark urine
- Pale stool (feces)
- Jaundice (yellow color to the whites of the eyes or skin)
Most infected people get well, but some develop chronic, long-term hepatitis B and can spread the infection to other people. Most people with chronic hepatitis B do not have any symptoms, do not feel ill, and can remain symptom free for many years. If a person with chronic hepatitis B does have symptoms, they will be similar to the symptoms of acute infection, but symptoms can be a sign of advanced liver disease. Some people still do not have symptoms even as the liver becomes diseased, but certain blood tests for liver function will show that something is not right.
Many people with hepatitis B do not know they are infected since they do not look or feel sick, yet they can still spread the virus to others. Acute infection can lead to chronic infection, which can cause cirrhosis (scarring of the liver), liver cancer, liver failure, and death. During childbirth, a mother may pass hepatitis B to her baby. Newborns infected with hepatitis B have a 90 percent chance of developing chronic hepatitis B. Between 4,000 and 5,000 people die each year in the U.S. from liver disease caused by hepatitis B.
If you are exposed to hepatitis B or get sick with it, call your healthcare provider or local health department. If you haven't been vaccinated against hepatitis B and you've been exposed recently, you can get hepatitis B vaccine or immune globulin. You need to do this within 24 hours to help prevent infection with the hepatitis B virus.
There is no medical treatment for acute hepatitis B. Doctors recommend a sick person rest, get good nutrition, and drink fluids. Some people may need to be hospitalized.
People with chronic hepatitis B need to be under the care of a doctor who has experience treating hepatitis B. They need regular monitoring for signs of liver disease and evaluation for possible treatment. Chronic hepatitis B is treated with several approved medications, but once medication is started, the infected person will need to take medication for life.
Yes, hepatitis B is contagious. The hepatitis B virus is spread to others by direct contact with infected blood, semen, or other bodily fluids. The hepatitis B virus can survive outside the body for at least 7 days, and may be able to cause infection. People can get infected from the following ways:
- Birth (spread from an infected mother to her baby)
- Sex with a partner who has hepatitis B
- Sharing needles, syringes, or drug preparation equipment
- Sharing items such as toothbrushes, razors or medical equipment such as a glucose monitor with a person who has hepatitis B
- Direct contact with the blood or open sores of a person who has hepatitis B
- Exposure to the blood from a person who has hepatitis B through needle sticks or other sharp instruments
Hepatitis B virus does not spread through food or water, sharing eating utensils, breastfeeding, hugging, kissing, hand holding, coughing, or sneezing.
If your body has cleared the virus from a past infection, you cannot get re-infected with hepatitis B. However, some people infected during early childhood remain infected for life because they never clear the virus from their bodies. You can get a blood test to tell if you have ever been infected and are now immune, or if you are still infected with the hepatitis B virus.
Anyone can get Hepatitis B, but some people are at greater risk and include:
- Infants born to a person infected with hepatitis B
- People who inject drugs or share needles, syringes, or other drug equipment
- Sex with a partner who has hepatitis B
- Men who have sex with men
- People who live with a person who has hepatitis B
- Health care and public safety workers exposed to blood on the job
- People on dialysis (experiencing kidney failure)
- Developmentally disabled people who live in long-term care facilities
- People in prison
- People with diabetes, chronic liver disease, HIV infection, or hepatitis C infection
- Travelers to countries with high rates of hepatitis B
The best way to prevent hepatitis B is by getting vaccinated. You must complete the series of shots for full protection. All infants should receive their first dose of the hepatitis B vaccine within 24 hours of birth, followed by a second dose at 1 to 2 months, and a third dose at 6 to 18 months. Infants who did not receive a birth dose should begin the series as soon as possible.
All unvaccinated children and adolescents younger than 19 years of age should get vaccinated.
All adults 19 through 59 years of age are recommended to get vaccinated.
Adults 60 years and older with risk factors should get vaccinated.
A combination vaccine that provides protection against both hepatitis A and B is available for those age 18 years and older. This vaccine is a series of 3 shots over a period of 6 months.
Immune globulin gives short-term prevention of hepatitis B in people of all ages recently exposed to hepatitis B, but the vaccine is preferred for long-term prevention.
Hepatitis B (PDF) (Centers for Disease Control and Prevention)
Printable Hepatitis B Fact Sheets (Hepatitis B Foundation)
Pink Book chapter on hepatitis B (Epidemiology and Prevention of Vaccine-Preventable Diseases, CDC)
Hepatitis B (CDC)
Hepatitis B (CDC)
Hepatitis B (International Community Health Services)
Ask the experts: hepatitis B (Immunization Action Coalition)
Hepatitis B (American Liver Foundation)
Hepatitis B (Hepatitis Foundation International)