Hepatitis B guide

Hepatitis B Testing

How do I get tested for hepatitis B?

We make getting tested for hepatitis B simple. We offer the highly accurate and reliable Hepatitis B Surface Antigen (HBsAg) blood test that provides early detection of acute or chronic hepatitis B infections...typically within 6 to 10 weeks of exposure and sometimes sooner, often before symptoms appear. Best of all, the test is easy and safe (no undressing or swabbing required!).

What hepatitis B Test results mean

A positive hepatitis B Test result means that you may have an active hepatitis B infection. A negative hepatitis B Test result means that the virus was not detected in your blood. But because hepatitis B may not yet be detectable if you get tested too soon after possible exposure to the virus, you'll want to get tested again three months after exposure to confirm that you're negative...repeat testing is critical to ensure the most accurate diagnosis.

If you test positive, we're here to help. You'll have the opportunity to consult with a doctor on the phone right away. We'll answer your questions and help you determine the next steps based on your specific circumstances.

Note: As with HIV and hepatitis C, if you test positive for hepatitis B, you should not donate blood.

Understanding false-positive or false-negative test results

As with most medical tests, there's a slight chance (1-4%) that a positive test result indicates an infection when there isn't one (false-positive); or a test comes back negative, despite the presence of infection (false-negative). For example, a false-negative test result can happen if an infected person tests too early for an infection to be detected...that means it's possible to get a negative test result but still have an STD.

If you're concerned about the reliability of your test results for any reason (e.g., timing, or your sexual history, or your partner's sexual history), we recommend that you get re-tested three months after possible exposure to the virus to confirm your results...and to minimize the risk of being a carrier and potentially developing more serious symptoms down the road.

Learn more about "testing windows" – the recommended amount of time between potential exposure to an STD infection, and when screening is expected to identify the infection (or re-infection); for example, if you had unprotected sex last night and became infected with hepatitis B, the virus wouldn't necessarily show up right away...it can take up to three months to test positive.

Last reviewed by Lisa Oldson, MD, January 2011.

Lisa Oldson, MD

STD expert

"The first thing I tell a patient about STDs is that if you're worried about one STD, you should probably worry about all STDs. In other words, if you had unprotected sex and you're worried about a possible HIV exposure, it's important to understand that hepatitis can be spread in the same fashion...ditto for chlamydia, gonorrhea, herpes and syphilis."