What Is Hepatitis B?

By Temma Ehrenfeld  @temmaehrenfeld
June 27, 2023
What Is Hepatitis B?

Hepatitis B, which attacks your liver, can hide in your body. You may not know you have the virus, and you can unknowingly transmit it to others.

Hepatitis B is a sneaky virus. You may not know you have it, and you can unknowingly pass it on to others. It hides in the nucleus of your cells and can attack your liver over many years, causing potentially serious damage.


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How do you get hepatitis B?

The virus travels from one person to another through fluids — nearly always in blood or semen. You might get it from unprotected sex with a man, if his semen enters your body and the virus gets through a tear in your skin in your vagina or anus. When heroin users share a needle or syringe, they can pass the virus through their blood. You might get hepatitis B from a stranger’s blood when receiving a tattoo. (If you go to a tattoo parlor, ask about their safety practices). You could possibly even get it from sharing a razor or toothbrush.

You cannot get hepatitis B from:

  • Food or water
  • Sharing eating utensils
  • Breastfeeding
  • Hugging
  • Kissing
  • Holding hands
  • Coughing
  • Sneezing
  • Insect bites

If you skip vaccination, know that carriers spread the disease to other people who are vulnerable.   

What are the symptoms of hepatitis B?

Around the world, most infections happen to unvaccinated babies or children and don’t have obvious symptoms. About 95 percent of infections resolve on their own without treatment.

When symptoms of hepatitis B occur, they can look like a flu (fever, joint pain, fatigue, nausea, or vomiting) and can last for weeks. You might see dark urine, clay-like feces, or a yellow tinge in your skin and eyes. If you see those symptoms in a child, especially one who has not been vaccinated, see a doctor immediately. 

Hepatitis B prevention

Beginning in 1991, the U.S. Advisory Committee on Immunization Practices recommended that all infants receive a vaccine to trigger a protective immune response. It works in 90 percent of recipients. Since 1991, new cases of hepatitis B have declined by 82 percent. Hepatitis B vaccination is a major public-health success.

The protection can decline over time, and scientists have been investigating whether booster shots should become routine. There isn’t enough research yet to answer that question.

About 10 percent of people don’t respond adequately to the vaccine, and some children never get it. If you or your child haven’t been vaccinated for hepatitis B, talk to your doctor or your child’s pediatrician to discuss your concerns.

A chronic, hidden infection won’t have symptoms during the early stages, but it will show up on a blood test.

Hepatitis B prevention should start with pregnancy. Get a screening before birth. If you have an infection, your baby should be vaccinated within 12 hours of birth.

Also get tested if you:

  • Have sex or live with someone who could be infected
  • Have ever shared needles
  • Have been institutionalized
  • Are an active homosexual male
  • Are exposed to infected people at work
  • Are receiving blood transfusions or chemotherapy

People born in Africa, Asia, India, Pakistan, or Eastern Europe have a higher risk.

If you suspect you (or your child) may have been exposed, go to a clinic or your doctor’s office. You may not recall whether you’ve been vaccinated, or you may not have responded adequately to a shot — or its effects may have waned.

Getting an injection of hepatitis B immune globulin within 12 hours of coming in contact with the virus may protect you. Also get vaccinated at the same time.





June 27, 2023

Reviewed By:  

Christopher Nystuen, MD, MBA