Test Quick Guide

Hepatitis B Surface Antigen (HBsAg) testing detects proteins on the hepatitis B virus to identify a current infection. Additional serologic markers, such as core antibody and surface antibody, may also be evaluated to determine whether a person has a past infection or immunity from vaccination.

Hepatitis B is a viral infection that causes inflammation of the liver. Hepatitis B testing can determine whether a person has a current infection, evidence of a previous infection, or protection from vaccination. The hepatitis B virus (HBV) spreads through contact with infected body fluids, most often through blood-to-blood exposure.

Hepatitis B infections may be acute or chronic. Acute hepatitis B is usually a short-term illness, and most people recover fully within several weeks to six months without treatment. In about 5 to 10% of cases, the infection becomes chronic, meaning it lasts longer than six months. Chronic hepatitis B can increase the risk of serious health problems, including liver damage, liver failure, and liver cancer.

The CDC now recommends that all adults age 18 and older be screened for hepatitis B at least once in their lifetime, in addition to ongoing testing for people at increased risk.

About Our Hepatitis B Test

Purpose of our hepatitis B test

Hepatitis B testing is used to detect current infection, confirm past exposure, evaluate immunity, and monitor ongoing hepatitis B disease.

  • Screening for HBV: Screening identifies hepatitis B in people without symptoms, allowing for early detection, treatment, and prevention of spreading the virus to others.
  • Diagnosing HBV infection: Testing confirms whether an infection is present, determines if it is acute or chronic, and assesses the potential to transmit the virus.
  • Assessing immunity: Tests can show whether a person is immune due to vaccination or recovery from a previous infection.
  • Monitoring HBV: After diagnosis, testing helps track the infection, detect complications, and evaluate response to treatment.

What does our hepatitis B test measure?

Hepatitis B testing looks for antigens, antibodies, or the genetic material of HBV. Antigens are substances from the virus that trigger an immune response. Antibodies are proteins made by the immune system in response to infection or vaccination.

Initial tests for hepatitis B measure antibodies and antigens related to HBV, including:

  • Hepatitis B surface antigen (HBsAg): Proteins present on the surface of HBV. These can be detected in high levels during both acute and chronic infections. This test is commonly used to screen for and diagnose active HBV infections.
  • Hepatitis B surface antibody (anti-HBs): These antibodies develop in response to HBsAg. Detecting anti-HBs suggests recovery from hepatitis B and immunity to the disease. They are also detected after successful vaccination.
  • Total hepatitis B core antibody (anti-HBc): These antibodies appear as symptoms develop and remain detectable for life. Results help differentiate between acute and chronic infections and indicate prior exposure to the virus.
  • IgM hepatitis B core antibody (IgM anti-HBc): This test detects antibodies present only in acute hepatitis B infections within six months of infection.

If initial tests indicate infection, additional testing may include:

  • Hepatitis B e antigen (HBeAg): Helps doctors understand infectivity and the ability to spread HBV to others.
  • Hepatitis B e antibody (anti-HBe): The presence of this antibody often suggests improvement and possible long-term clearance of the virus.
  • Hepatitis B viral DNA: Detects the virus’s genetic material and determines viral load. This test is often used to monitor treatment effectiveness in people with chronic hepatitis B.

When should I get a hepatitis B test?

Hepatitis B screening is recommended for all adults at least once, and additional testing is advised for people at increased risk of infection. You may benefit from testing if you:

  • Are pregnant
  • Were born in regions where hepatitis B is more common
  • Did not receive a hepatitis B vaccine
  • Are HIV-positive
  • Use injectable drugs
  • Have had unprotected sexual contact or multiple sexual partners
  • Live with or have close contact with someone who has hepatitis B
  • Have elevated liver enzyme levels
  • Are receiving immunosuppressive therapy or have kidney disease

More details on risk-based testing: https://www.cdc.gov/hepatitis/hbv/testingchronic.htm

A doctor may also recommend testing based on symptoms such as:

  • Dark urine
  • Fatigue
  • Fever
  • Gray- or clay-colored stools
  • Loss of appetite, nausea, or vomiting
  • Abdominal or joint pain
  • Yellowing of the skin or eyes

Testing may also be performed to assess immunity before or after vaccination, particularly in high-risk individuals.

 

Finding a Hepatitis B Test

How to get tested

Hepatitis B testing is typically prescribed by a doctor and performed in a hospital, lab, or medical clinic. Testing requires a blood sample collected by a health care professional. Fasting is not required.

For laboratory testing, blood is drawn from a vein and sent to a lab for analysis. The test can also be ordered online.

Can I take the test at home?

At-home hepatitis B testing is available and usually involves collecting a small blood sample using a fingerstick. The sample is mailed to a laboratory for analysis.

Many at-home kits test only for HBsAg. These tests do not evaluate immunity or prior exposure, so it is important to review what components are included before purchasing.

How much does the test cost?

The cost depends on the specific tests performed, where testing is conducted, and whether you have health insurance. Insurance often covers testing ordered by a doctor, though copays and deductibles may apply.

For those without insurance, discussing costs with a doctor or hospital administrator may help identify affordable options.

Taking a Hepatitis B Test

Testing for hepatitis B is performed on a sample of blood collected by a doctor, nurse, or other health care provider. Fasting is not required.

At-home testing requires careful adherence to the instructions provided in the test kit.

Before the test

No special preparation is required. Inform your doctor about any medications or supplements you are taking.

During the test

A blood draw generally involves:

  • Locating a vein in the arm or hand
  • Cleaning the puncture site
  • Inserting a small needle and collecting blood

The process typically takes less than five minutes. Mild discomfort or bruising may occur.

For infants, young children, or at-home tests, a fingerstick method may be used instead.

After the test

A bandage is applied to the puncture site. There are no restrictions on activities after testing.

FAQs About a Hepatitis B Test

What should I do if I think I’ve been exposed to hepatitis B?

If you believe you may have been exposed to hepatitis B, testing as soon as possible can help determine whether an infection is present. In some cases, preventive treatment may be available shortly after exposure. Contact a healthcare provider promptly to discuss testing and whether follow-up care or vaccination is appropriate.

How and when will I receive my test results?

Results from a hepatitis B blood test are typically available within a few business days, depending on the laboratory. If your test was ordered by a doctor, results are usually shared through a follow-up appointment, patient portal, phone call or secure email. At-home test results are generally delivered through the testing company’s online platform once the lab completes analysis.

What does a positive hepatitis B test mean?

A positive result may indicate a current hepatitis B infection, but the exact meaning depends on which marker is tested. For example, a positive hepatitis B surface antigen test suggests an active infection, while other tests help determine whether the infection is new, long-standing or resolved. Your healthcare provider can review your results and recommend any additional testing needed to clarify your status.

What happens if I test positive for hepatitis B?

If testing shows an active hepatitis B infection, your healthcare provider will discuss next steps. This may include additional blood tests to evaluate liver function and viral activity, monitoring over time or referral to a specialist. Many people with hepatitis B can manage the condition effectively with regular care, and early follow-up helps reduce the risk of complications.

Can a negative test rule out hepatitis B completely?

A negative result usually means there is no current infection, but very recent exposures may not appear on tests right away. If you were tested soon after a possible exposure, your provider may recommend repeat testing after several weeks. Testing can also determine whether you are immune and would benefit from hepatitis B vaccination.

Related Tests