Hepatitis B (Hep B) Virus

Overview

What Is Hepatitis B?

Hepatitis B, also called Hep B, is a liver infection caused by the hepatitis (heh -puh-TYE-tus) B virus (HBV). For some people, it’s a short illness that clears up with no problems. For others, it can cause long-lasting disease and long-term liver problems.

The hepatitis B vaccine helps prevent HBV and can be given shortly after birth.

What’s the Difference Between Acute Hepatitis B & Chronic Hepatitis B?

Doctors refer to hepatitis B infections as either acute or chronic:

Acute hepatitis B is a short-term illness that happens within six months of when a person is exposed to the virus.
Chronic hepatitis B is when a person still has the virus in their body after six months. This means the virus stays in the body and can cause lifelong illness.

The younger someone is when infected with the virus, the greater their chances of developing chronic hepatitis B and having lifelong illness. About 90% of babies with HBV will develop a chronic infection.

Because of this, the American Academy of Pediatrics (AAP) recommends that all babies get the first dose of the hepatitis B vaccine within 12–24 hours of birth. They'll get two more doses later, at 1–2 months of age and at 6–18 months of age.

Signs & Symptoms

What Are the Signs & Symptoms of Acute Hepatitis B Infection?

HBV can cause a range of symptoms, from a mild illness and a general feeling of being unwell to more serious chronic liver disease. Chronic hepatitis B can lead to liver cancer, liver failure, and death.

Someone with acute hepatitis B may have symptoms similar to those caused by other viral infections, like the flu. They might:

be extra tired
feel nauseous (like throwing up) or throw up
not feel like eating
have a mild fever

HBV also can cause darker than usual pee, light or grey-colored stools (poop), jaundice (when the skin and whites of the eyes look yellow), joint pain, and belly pain.

People exposed to hepatitis B may start to have symptoms within one to six months. Symptoms can last for weeks to months.

In some people, hepatitis B causes few or no symptoms. But even someone who has no symptoms can still spread the disease to others, and can still develop chronic hepatitis B and long-term problems. Those who develop chronic hepatitis B may not have any symptoms, may have similar symptoms to acute hepatitis B, or may develop symptoms of liver failure. Liver failure can cause serious problems, such as confusion, bleeding, weight loss, pain, and swelling.

What Problems Can Hepatitis B Cause?

Chronic hepatitis B is a serious infection. It can lead to cirrhosis (permanent scarring) of the liver, liver failure, or liver cancer, which can cause severe illness and even death.

If a pregnant woman has hepatitis B, even with no symptoms, her baby has a very high chance of catching it at birth or just after, unless the baby gets a special immune injection and the first dose of hepatitis B vaccine shortly after birth.

Sometimes, HBV doesn't cause symptoms until a person has had the infection for a while. At that stage, they already might have more serious problems, like liver damage.

Causes & Prevention

How Do People Get Hepatitis B?

Hepatitis B virus spreads through:

HBV-infected mothers passing the virus to their newborn babies
sexual activity with an HBV-infected person
shared contaminated needles or syringes used for injecting drugs
shared toothbrushes, razors, or other items that could have small amounts of blood on them

Can Hepatitis B Be Prevented?

Yes. Newborn babies in the United States can get the hepatitis B vaccine as a series of three shots over a six-month period. There's been a big drop in the number of cases of hepatitis B thanks to immunization.

Doctors also recommend "catch-up" vaccination for all kids and teens younger than 19 years old who didn't get the vaccine as babies or didn't get all three doses. Some kids may need to be revaccinated later in life. These include children:

whose mothers carry the hepatitis B virus in their blood
who need hemodialysis
who have a weak immune system

If someone who hasn't been vaccinated is exposed to HBV, doctors may give the vaccine and/or a shot of immune globulin containing antibodies against the virus to try to prevent infection. That's why it's very important to see a doctor right away after any possible exposure to the virus.

To prevent the spread of hepatitis B through infected blood and other body fluids, adults and teens should:

always use latex condoms when having sex (oral, vaginal, or anal)
avoid contact with an infected person's blood
not use intravenous drugs, share needles, or other drug tools
not share things like toothbrushes or razors
research tattoo and piercing places carefully to make sure they don't reuse needles without properly sterilizing them

Diagnosis

How Is Hepatitis B Diagnosed?

Someone with symptoms, or someone who might have been exposed to the virus through sex or drug use, should see a doctor right away for a blood test. It’s routine for those who are pregnant to be tested as well.

A blood test checks blood for antibodies to the virus, and can help doctors determine if someone has an acute infection or a chronic infection. Examined together, the results of the blood test help doctors diagnose hepatitis B.

Treatment & Care

How Is Hepatitis B Treated?

There's no cure for hepatitis B. Doctors will offer advice on how to manage symptoms — like getting plenty of rest or drinking fluids. A person who is too sick to eat or drink will need treatment in a hospital.

In most cases, older kids and teens who get hepatitis B recover and feel better within six months. Healthcare providers will keep a close eye on patients who develop chronic hepatitis B. They can sometimes treat it with antiviral medicine.

What Else Do I Need to Know?

Some people carry the virus in their bodies and are contagious for the rest of their lives. They should not drink alcohol, and should check with their doctor before taking any medicines (prescription, over-the-counter, or supplements) to make sure these won't cause more liver damage.

Anyone who has ever tested positive for hepatitis B cannot be a blood donor.