Cancerwise

Hepatitis B (HBV) is a common viral infection that targets liver cells. According to the World Health Organization, about a third of the world’s population had been exposed to it as of June 2026, and roughly 254 million people have a chronic hepatitis B infection.

But how serious is hepatitis B? Can you catch it just by kissing someone? And can hepatitis B be cured? Here’s what you need to know.

What is the main cause of hepatitis B?

Most people contract hepatitis B through exposure to infected blood or semen/vaginal secretions. That could be from:

• Having unprotected sex
• Sharing intravenous drug needles
• Exposure to contaminated blood products (usually as a healthcare worker)
• Being born vaginally to a mother who is infected

What are the symptoms of hepatitis B?

Chronic hepatitis B often doesn’t have any symptoms until the disease is fairly advanced.

Acute hepatitis B, on the other hand, can cause fever, fatigue, jaundice, dark urine and abdominal pain.

Can I get hepatitis B just by kissing someone?

No. Hepatitis B is spread through infected blood, semen, and vaginal secretions, not saliva. So, you can’t get it just by hugging someone or even kissing someone who's infected, unless you both have open wounds in your mouths.

Is hepatitis B considered serious?

Yes. Hepatitis B is associated with three things that can cause significant liver damage:

• Inflammation
• Fibrosis (hardening of liver tissue)
• Cirrhosis (scarring of liver tissue)

It is also a leading cause of liver cancer, which is one of the deadliest cancers. It increases your risk of certain other cancers, too, including some B-cell lymphomas.

Hepatitis B is most concerning if you’re an adult with a chronic infection, as that requires treatment for life. It also requires regular screening for liver cancer.

The good news is that you can reduce your risk of both liver damage and liver cancer if you get treated with antiviral therapy. And roughly 60% of all liver cancers are still preventable through lifestyle modification.

How long can a person live with hepatitis B?

In most cases, hepatitis B is a silent infection. That means it doesn’t cause any obvious symptoms until it’s fairly advanced. So, you could have it for maybe 20 or 30 years before anything happens. That’s why many people with chronic hepatitis B end up dying of something else.

But some of our patients actually come to UT MD Anderson for the treatment of one kind of cancer, then end up developing a second type due to viral hepatitis. So, the challenge is detecting hepatitis B early and keeping the people who don’t realize they have it from passing it on to anyone else.

Who should get screened for hepatitis B?

The Centers for Disease Control and Prevention (CDC) now recommends that all adults be screened for hepatitis B at least once in their lifetime. But it’s not part of any regular health screening yet, and it is not detected through routine bloodwork. So, you have to ask for it.

Screening is done through a blood test that looks for three things:

• Hepatitis B surface antigen (HBsAg)
• Hepatitis B surface antibody
• Hepatitis B core antibody

A positive or reactive HBsAg result means the virus is present in your blood. If the hepatitis B core antibody is present, it may suggest that you’ve been exposed to this virus. If you've received either of these results, it's important to follow up with a doctor to determine whether you have been exposed to the virus and if you have an active infection.

Should I get the hepatitis B vaccine?

Yes, if you’ve never been exposed to it, your surface antibody test is negative, and you haven’t been vaccinated. The vaccine is the safest, most effective way to protect yourself from infection and its complications.

Is hepatitis B curable?

For acute cases, yes. These are usually self-limiting.

For chronic cases, the answer is no, not yet. But more than 30 different drugs are currently being tested. It’s a very active field. We also have two antiviral drugs here in the U.S. that can significantly reduce the amount of virus circulating in your body: entecavir and tenofovir.

If we can reduce and keep your viral load (hepatitis B DNA level) undetectable using current tests, we may be able to reduce the liver-related complications of the disease. But you will still have it until a cure is found.

Harrys Torres, M.D., is an infectious disease specialist at UT MD Anderson.

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