About the Test
Purpose of the test
Hepatitis B is a viral infection that causes inflammation of the liver. Test results can identify present hepatitis B infection, past exposure to HBV, or immunity to the virus.
HBV is spread through contact with body fluids. Most frequently, it is spread from blood-to-blood contact, but it may be transmitted through other body fluids. Common forms of exposure to HBV vary based on geographical area but often occur during childbirth and infancy, when sharing needles for intravenous drug use, or during unprotected sex.
A hepatitis B infection can be acute or chronic. Acute hepatitis B is a short-lived infection. You can usually recover completely from acute hepatitis B without treatment within a few weeks to six months.
Around 5 to 10% of patients with acute hepatitis B progress to having chronic hepatitis B, a long-term infection lasting six months or longer. If you have chronic hepatitis B, you are at an increased risk of developing complications, including severe damage to the liver, liver failure, and liver cancer.
A doctor may order hepatitis B testing for several purposes:
- Screening for HBV: Screening tests attempt to find a disease before a person develops symptoms. Many people with hepatitis B have no symptoms, so screening for this disease enables early detection so you can receive treatment and avoid unknowingly spreading the virus to others. Hepatitis B screening may be recommended if you are at an increased risk of contracting this infection.
- Diagnosing and evaluating HBV infection: Hepatitis B testing can identify whether you have a current hepatitis B infection, if it is acute or chronic, and whether you can spread the virus to others.
- Assessing past HBV infection and future immunity: Tests for hepatitis B can show whether you are immune either due to HBV vaccination or having recovered from a past infection. Hepatitis B testing may also be used to assess whether vaccination successfully generated immunity and to identify who is at an increased risk of HBV reactivation.
- Monitoring HBV infections: Testing may be used after a person is diagnosed with hepatitis B to monitor the disease, detect complications, and assess response to treatment.
What does the test measure?
Hepatitis B testing looks for antigens, antibodies, or the genetic material of HBV. Antigens of HBV are substances from the virus that cause your body to produce an immune response. Antibodies are substances made by the immune system in response to HBV.
Initial tests for hepatitis B measure antibodies and antigens related to HBV including:
- Hepatitis B surface antigen (HBsAg): These are proteins present on the surface of HBV. The proteins can be detected in high levels during both an acute or chronic hepatitis B infection. This test may be used to screen for, detect, and help diagnose acute and chronic HBV infections.
- Hepatitis B surface antibody (anti-HBs): In response to HBsAg, the body naturally produces surface antibodies within a few weeks or months. Detecting anti-HBs suggests that you have recovered from hepatitis B and are now immune to the disease. These antibodies are also detected in those who have previous exposure to HBV, including through vaccination.
- Total hepatitis B core antibody (anti-HBc): Hepatitis B core antibodies appear as you develop symptoms of hepatitis, and they remain detectable for life. The results of this test are interpreted alongside other tests to assess recovery from a previous HBV infection and to differentiate between acute and chronic infections. This test detects two types of anti-HBc antibodies, called IgM and IgG anti-HBc antibodies.
- IgM Hepatitis B core antibody (IgM anti-HBc): This test detects only IgM anti-HBc antibodies. IgM Hepatitis B core antibody is detected only in acute hepatitis B infections within six months of infection.
If you are diagnosed with hepatitis B based on these initial tests, additional testing may be used to monitor the disease, guide treatment, and determine if you can spread hepatitis B to others. These additional tests may include:
- Hepatitis B e antigen (HBeAg): This is a protein from HBV found in some patients who are positive for HBsAg. Measuring this antigen can help doctors understand infectivity, your ability to spread HBV to others.
- Hepatitis B e antibody (anti-HBe): This is produced in response to HBeAg. The disappearance of HBeAg and detection of anti-HBe in the blood, called seroconversion, suggests improvement of the condition and predicts long-term clearance of the virus. Chronic liver disease is more common in those with HBeAg and is less common with anti-HBe, so this test may monitor acute HBV infections.
- Hepatitis B viral DNA: A hepatitis B viral DNA test detects the virus’s genetic material and determines the viral load in the blood. A positive test indicates that the virus is multiplying in a person’s body, making that person contagious. The test is often used to monitor the effectiveness of antiviral therapy in people with chronic HBV infections.
When should I get this test?
Using hepatitis B tests to screen for HBV is recommended for certain groups at an increased risk of infection. You may benefit from hepatitis B screening if you:
- Are pregnant
- Were born in parts of the world where the disease is more common, including Africa, Asia, Eastern Europe, South America, and parts of the Middle East
- Didn’t receive a hepatitis B vaccine
- Are HIV-positive
- Use injectable drugs
- Are at risk of HBV infection due to sexual exposure
A doctor may order hepatitis testing based on your symptoms, medical and family history, and a physical exam. If you develop symptoms without recent exposure to HBV, doctors may recommend an acute viral hepatitis panel that looks for hepatitis A, B, and C in one sample of blood.
Hepatitis tests may also be performed as follow-up tests when other tests of liver health are abnormal.
Testing is common in those that show symptoms that could be caused by hepatitis B. Symptoms of hepatitis B include:
- Dark urine
- Fatigue
- Fever
- Gray- or clay-colored stools
- Loss of appetite, nausea, or vomiting
- Pain in the joints or abdomen
- Yellowish skin and eyes
Using hepatitis B testing to assess immunity to HBV may take place before or after vaccination. Pre-vaccination testing is not always needed but may be performed if there is a chance that you have previously been infected with HBV or have already been vaccinated. Post-vaccination testing is used in certain groups of people at an especially elevated risk for HBV infection, including infants born to mothers with a hepatitis B infection.
Finding a Hepatitis B Test
How can I get a hepatitis B test?
Hepatitis B testing is typically prescribed by a doctor and performed in a hospital, lab, or another medical setting. Taking a hepatitis B test requires a blood sample, which can be collected by a health care professional.
For laboratory-based testing, blood is drawn from your vein. After blood is collected, the sample is sent to a laboratory for analysis.
The test can also be ordered online.
Can I take the test at home?
Samples for hepatitis B testing can be collected at home. At-home hepatitis B testing requires you to collect a blood sample, typically from a fingerstick using a very small needle provided in the test kit. Once a blood sample is collected, it is prepared according to the instructions contained in the test kit and mailed to a laboratory for testing.
Because there are numerous types of tests for HBV, it is important to look closely at the specific components of any at-home test kit. Many at-home test kits only look for HBsAg.
How much does the test cost?
The cost of hepatitis B testing depends on the tests performed, where the test is conducted, and your health insurance coverage. When testing is ordered by a doctor, you may find it helpful to discuss the cost of testing with their health insurance company as they may be responsible for testing costs as well as other out-of-pocket expenses such as copays and deductibles.
For those without health insurance or for whom insurance doesn’t cover the cost of testing, it may be helpful to discuss the cost of hepatitis B testing with a doctor or hospital administrator.
Taking a Hepatitis B Test
Testing for hepatitis B is performed on a sample of blood. A doctor, nurse, or other health care provider can obtain a blood sample using a small needle to draw blood from a vein.
At-home hepatitis B testing requires that users carefully follow instructions provided in the test kit to collect a small sample of blood, package the sample, and mail it to a lab for testing.
Before the test
No special preparation is required before hepatitis B testing. However, it’s important for you to tell your doctor about any medications you are taking, including both prescription and over-the-counter drugs.
During the test
For laboratory-based testing, collecting a blood sample involves several steps:
- Locating an appropriate vein, often on the arm or hand
- Tying a tourniquet around the upper arm to increase blood flow
- Cleaning the puncture site, usually with an antiseptic wipe
- Inserting a small needle into a vein and drawing blood into an attached vial
Collecting blood often takes less than five minutes. Side effects of a blood draw include mild discomfort or stinging when the needle is inserted as well as temporary throbbing and bruising.
Sometimes a drop of blood is collected by puncturing the skin with a small tool called a lancet. This method may be used with infants, young children, and for at-home hepatitis B testing. After puncturing the skin, several drops of blood are collected in a small tube or vial.
At-home test kits vary, and it’s important to read all the instructions before collecting your blood sample.
After the test
Once the blood sample is collected, a bandage or piece of gauze is applied to the puncture site. There are no restrictions on your activities after a blood draw or skin puncture.
Hepatitis B Test Results
Receiving test results
When a blood sample is collected during a blood draw, testing is often completed and reported to you within a few business days. You can schedule a follow-up appointment to discuss results and have an opportunity to ask questions about test results. You may also receive test results by phone, mail, or through an electronic medical record.
At-home hepatitis B test results may be available within a few business days after the laboratory receives the test sample. At-home test results may be shared through the testing company’s website or smartphone app, and many companies offer a consultation with a doctor if the results of at-home testing are abnormal.
Interpreting test results
As hepatitis B testing can be used for many different purposes, it’s important to work with a doctor or specialist when interpreting test results, which are typically evaluated together. Some of the potential interpretations of initial hepatitis B test results include:
Initial Hepatitis B Testing
| Hepatitis B surface antigen (HBsAg) | Hepatitis B surface antibody (anti-HBs) | Total Hepatitis B core antibody (anti-HBc) | IgM Hepatitis B core antibody (IgM anti-HBc) | Possible Interpretation |
|---|---|---|---|---|
| Negative | Negative | Negative | Negative | No active or prior infection; not immune |
| Negative | Positive | Negative | Not performed | Immune due to vaccination |
| Negative | Positive | Positive | Not performed | Immune due to resolved infection |
| Positive | Negative | Positive | Positive | Acute infection |
| Negative | Negative | Positive | Positive or negative | Several possible interpretations |
| Positive | Negative | Positive | Negative | Chronic infection |
Additional hepatitis B tests help doctors monitor the disease, direct treatment, and determine if you are contagious. Interpreting the results of these additional hepatitis B tests is complex and often interpreted alongside other tests, so it’s important to work with a doctor or specialist to understand what results mean for your health.
You may find it helpful to ask questions about your hepatitis B test results. Questions that may be helpful include:
- What was my test result?
- Do I have an acute or chronic hepatitis B infection?
- Does the test result suggest that I have immunity for hepatitis B?
- Would I benefit from hepatitis B vaccination?
- Do I need any follow-up tests based on my hepatitis B test results?
