Hepatitis B
Exams and Tests
Your doctor will diagnose hepatitis B virus (HBV) infection based on a physical examination, your medical history, and blood tests. You will be asked questions about risk factors for hepatitis B (such as about your job or sexual activity) and about factors that could make the disease worse (such as your alcohol use or family history of liver cancer).
If your doctor thinks you may be infected with the virus, you will need tests to find out more about your condition.
Blood tests done to help diagnose hepatitis B include:
- Hepatitis B antigens and antibodies, which help tell whether you are or were infected with HBV, whether you have been immunized, and whether you have long-term (chronic) HBV infection. You also may get tested for hepatitis B viral DNA (HBV DNA), which detects genetic material (DNA) from the hepatitis B virus. HBV DNA indicates that the virus is multiplying in your body (active) and that you can pass the virus to others. For more information, see the topic Hepatitis B Virus Tests.
- Tests that determine whether the hepatitis A, hepatitis C, or Epstein-Barr (which causes infectious mononucleosis, or "mono") viruses are causing your hepatitis if the results of your tests show that HBV is not multiplying in your body.
- Tests that determine the cause of liver inflammation if it is not a viral cause.
- Tests that determine whether you are infected with hepatitis D along with hepatitis B.
Blood tests done to help determine if your liver has been damaged include:
- Bilirubin, albumin, and prothrombin time, which help determine how well your liver is functioning. Cholesterol testing also may be done.
- Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, and lactic dehydrogenase (LDH), which help determine whether your liver is damaged or inflamed. These tests measure enzymes produced by the liver. But these tests alone are not a reliable way to confirm a diagnosis of hepatitis B. Additional tests usually are needed.
Tests may be done if you have chronic HBV infection and are considering antiviral treatment. These tests also may be used to determine whether treatment has been helpful in controlling liver damage caused by chronic HBV infection. They include:
- Diagnostic imaging.
- Abdominal ultrasound
- CT scan
- MRI (may be used in rare cases)
- Removing a tissue sample from the liver (liver biopsy).
If you have chronic hepatitis B, the U.S. Centers for Disease Control and Prevention (CDC) recommends that you be vaccinated for hepatitis A if you have not been vaccinated or are not immune to this disease. For more information on Hepatitis A, see the topic Hepatitis A.
If you are at risk for liver cancer, an alpha-fetoprotein (AFP) test may be done. If the AFP level is elevated, it may indicate liver cancer.
If you have chronic HBV infection, you will need to visit your doctor regularly. He or she will do blood tests to monitor your liver function and the activity of the hepatitis B virus in your body. Some of the tests can tell your doctor whether HBV is actively multiplying in your liver, which increases your risk for chronic hepatitis. Chronic hepatitis can lead to cirrhosis or liver cancer (hepatocellular carcinoma).
Early Detection
The CDC recommends that all pregnant women have the hepatitis B surface antigen test. This test can tell if a woman has an active HBV infection. This test also may be repeated later in the pregnancy if a woman is at high risk for infection. For more information on risk factors, see the What Increases Your Risk section of this topic.
People who were exposed to the hepatitis B virus in the past, especially people who moved to the United States from a country where the virus is common, often develop lifelong protection (immunity) against HBV and do not need to be vaccinated. But people from countries where HBV infection is common may carry the virus and should be screened for the virus.
You can be tested for hepatitis B before getting vaccinated.
- Antibody testing will show if you have an active hepatitis B infection and need treatment.
- If testing shows you are already protected against hepatitis B, you will not need to get the hepatitis B vaccine
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- You can receive the hepatitis B vaccine even if you already have antibodies against HBV in your blood, and no harm will result.
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| Author: | Maria Essig | Last Updated: August 6, 2009 |
| Medical Review: |
Kathleen Romito, MD - Family Medicine
W. Thomas London, MD - Hepatology |
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