Hepatitis B

Medically Reviewed by Minesh Khatri, MD on August 14, 2023
9 min read

Hepatitis B is an infection of your liver. It’s caused by a virus. There is a vaccine that protects against it. For some people, hepatitis B is mild and lasts a short time. These “acute” cases don’t always need treatment. But it can become chronic. If that happens, it can cause scarring of the organ, liver failure, and cancer, and it even can be life-threatening.

It’s spread when people come in contact with the blood, open sores, or body fluids of someone who has the hepatitis B virus.

It's serious, but if you get the disease as an adult, it shouldn’t last a long time. Your body fights it off within a few months, and you’re immune for the rest of your life. That means you can't get it again. But if you get it at birth, it’s unlikely to go away.

Hepatitis” means inflammation of the liver. There are other types of hepatitis. Those caused by viruses also include hepatitis A and hepatitis C.

Short-term (acute) hepatitis B infection doesn’t always cause symptoms. For instance, it’s uncommon for children younger than 5 to have symptoms if they’re infected.

If you do have symptoms, they may include:

Symptoms may not show up until 1 to 6 months after you catch the virus. You might not feel anything. About a third of the people who have this disease don’t. They find out only through a blood test.

Symptoms of long-term (chronic) hepatitis B infection don’t always show up, either. If they do, they may be like those of short-term (acute) infection.

It’s caused by the hepatitis B virus, and it can spread from person to person in certain ways. You can spread the hepatitis B virus even if you don’t feel sick.

The most common ways to get hepatitis B include:

  • Sex. You can get it if you have unprotected sex with someone who has it and your partner’s blood, saliva, semen, or vaginal secretions enter your body.
  • Sharing needles. The virus spreads easily via needles and syringes contaminated with infected blood.
  • Accidental needle sticks.Health care workers and anyone else who comes in contact with human blood can get it this way.
  • Mother to child.Pregnant women with hepatitis B can pass it to their babies during childbirth. But there’s a vaccine to prevent newborns from becoming infected.

Hepatitis B doesn’t spread through kissing, food or water, shared utensils, coughing or sneezing, or through touch.

The number of people who get this disease is down, the CDC says. Rates have dropped from an average of 200,000 per year in the 1980s to around 14,000 in 2020. People between the ages of 20 and 49 are most likely to get it.

About 90% of infants and 25-50% of children between the ages of 1-5 will become chronically infected. In adults, approximately 95% will recover completely and will not go on to have a chronic infection.

As many as 1.2 million people in the U.S. are carriers of the virus.

If your doctor thinks you may have it, they’ll give you a complete physical exam. They will test your blood to see if your liver is inflamed. If you have hepatitis B symptoms and high levels of liver enzymes, you’ll be tested for:

  • Hepatitis B surface antigen and antibody (HBsAg). Antigens are proteins in the hepatitis B virus. Antibodies are proteins made by your immune cells. Antigens show up in your blood between 1 and 10 weeks after exposure. If you recover, they go away after 4 to 6 months. If they’re still there after 6 months, your condition is chronic.
  • Hepatitis B surface antibody (anti-HBs). These show up after HBsAg disappears. They’re what make you immune to hepatitis B for the rest of your life.

If your disease becomes chronic, your doctor might take a tissue sample from your liver, called a biopsy. This will tell them how severe your case is. You might also get a liver ultrasound to check on how much liver damage there is.

If you think you’ve been exposed to the virus, get to a doctor as soon as possible. The earlier you get treatment, the better. They’ll give you a vaccine and a shot of hepatitis B immune globulin. This protein boosts your immune system and helps it fight off the infection.

If you do get sick, you’ll have to give up things that can hurt your liver, like alcohol . Check with your doctor before taking any other drugs, herbal treatments, or supplements. Some of them can harm this organ, too. Also, eat a healthy diet.

If the infection goes away, the doctor will tell you you’re an inactive carrier. That means there’s no more virus in your body, but antibody tests will show that you had hepatitis B in the past.

If the infection is active for longer than 6 months, your doctor will tell you that you have chronic active hepatitis B. They may prescribe some of these medications to treat it:

  • Adefovir dipivoxil (Hepsera). This drug, which you take as a tablet, works well for people who don’t respond to lamivudine. High doses can cause kidney problems.
  • Entecavir (Baraclude). This is taken once a day with few side effects. It is considered the front-line treatment.
  • Interferon alfa (Intron A, Roferon A, Sylatron). This medicine boosts your immune system. You take it as a shot for at least 6 months. It treats liver inflammation but doesn’t cure the disease.
  • Lamivudine (3tc, Epivir A/F, Epivir HBV, Heptovir). It comes as a liquid or tablet you take once a day. Most people don’t have a problem with it. But if you take it for a long time, the virus might stop responding to the drug.
  • Pegylated Interferon (Pegasys)  Long-acting interferon, is given by injection once a week usually for 6 months to a year. But this drug can make you feel bad all over or depressed, and it can and zap your appetite. It also lowers your white blood cell count, which makes it harder to fight off infection.
  • Telbivudine (Tyzeka) is an antiviral medication. Resistance to this medication is common.
  • Tenofovir alafenamide (Vemlidy). These tablets are taken 6 to 12 months.
  • Tenofovir disoproxil fumarate (Viread). This drug comes as a powder or tablet. If you take it, your doctor will check often to make sure it doesn’t hurt your kidneys.

Although most people with chronic hepatitis B don’t feel sick or even know they have it unless it’s in its late stages, some do have serious complications. Chronic hepatitis B can lead to:

  • Cirrhosis, or scarring of the liver. This makes it harder for the liver to do its work and can eventually lead to liver failure.
  • Liver cancer. If you have chronic hepatitis B, your doctor may recommend that you get an ultrasound exam to see if there are any signs of liver cancer.
  • Liver failure. This is when your liver is no longer able to do its work. You may also hear it called “end-stage” liver disease. This only happens in severe cases of chronic hepatitis B.
  • Kidney disease. Researchers have found that people with cirrhosis caused by hepatitis B may be more likely to have certain types of kidney disease.
  • Blood vessel problems. These include inflammation of the blood vessels.

If you’re pregnant, you might pass the virus to your baby at birth.

If your baby gets the virus and isn’t treated, they could have long-term liver problems. All newborns with infected mothers should get hepatitis B immune globulin and the vaccine for hepatitis at birth and during their first year of life.

To help keep a hepatitis B infection from spreading:

  • Get the hepatitis B vaccine (if you haven’t already been infected). It’s key to prevention. The Centers for Disease Control & Prevention recommends universal hepatitis B vaccination for all adults aged 19 to 59 as well as for adults aged 60 years or older with known risk factors for hepatitis B virus infection. Those age 60 years or older, without known risk factors should be offered a HepB vaccine series.
  • Use condoms every time you have sex.
  • Wear gloves when you clean up after others, especially if you have to touch bandages, tampons, and linens.
  • Cover all open cuts or wounds.
  • Don’t share razors, toothbrushes, nail care tools, or pierced earrings with anyone.
  • Don’t share chewing gum, and don’t pre-chew food for a baby.
  • Make certain that any needles for drugs, ear piercing, or tattoos -- or tools for manicures and pedicures -- are properly sterilized.
  • Clean up blood with one part household bleach and 10 parts water.

The U.S. Preventive Services Task Force recommends that people in these groups get screened for hepatitis B:

  • All pregnant women
  • People born in countries or regions where hepatitis B is common
  • People born in the U.S. who weren’t vaccinated as babies and whose parents are from countries or regions where hepatitis B is common (such as sub-Saharan Africa and Southeast Asia)
  • People who are HIV-positive
  • People who inject drugs
  • Men who have sex with men
  • People who live with or have sex with someone who has hepatitis B
  • Blood and tissue donors
  • Infants born to someone with HBV infection

Donated blood is tested for the virus, so your chances of getting the disease from a transfusion are low. Any infected blood is discarded.

All newborn babies should get vaccinated. You should also get the shot if you:

  • Come in contact with infected blood or body fluids of friends or family members
  • Use needles to take recreational drugs
  • Have sex with more than one person
  • Are a health care worker
  • Work in a day-care center, school, or jail

There is no cure for hepatitis B. The outlook depends on whether you were infected as an infant or as an adult. As an adult, it usually goes away in a few months, and it sometimes disappears in people who have a chronic case of the disease.

Your doctor will know you’ve recovered when you no longer have symptoms and blood tests show:

  • Your liver is working normally.
  • You have hepatitis B surface antibody.

But some people don't get rid of the infection. If you have it for more than 6 months, you’re what’s called a carrier, even if you don’t have symptoms. This means you can give the disease to someone else through:

  • Unprotected sex
  • Contact with your blood or an open sore
  • Sharing needles or syringes

Doctors don’t know why, but the disease does go away in a small number of carriers. For others, it becomes what’s known as chronic. That means you have an ongoing liver infection. It can lead to cirrhosis, or hardening of the organ. It scars over and stops working. Some people also get liver cancer.

If you’re a carrier or are infected with hepatitis B, don’t donate blood, plasma, body organs, tissue, or sperm. Tell anyone you could infect -- whether it’s a sex partner, your doctor, or your dentist -- that you have it.