Hepatitis A, B, and C Blood Tests
What is hepatitis?
Hepatitis is a general term that means inflammation of the liver. Hepatitis A, B, and C are three of the main hepatitis viruses that can infect your liver. The liver is one of the largest organs and a very important part of your body. Some of the functions of the liver include:
- It helps your body get rid of some medicines and harmful substances.
- It makes bile, which helps your body digest fats.
- It stores sugar, which your body uses for energy.
- It makes many proteins, which are the building blocks for all cells in your body.
When you have hepatitis, the liver is irritated (inflamed). It may be swollen and tender. Areas of liver tissue may be destroyed.
Why are these tests done?
Hepatitis A, B, and C blood tests check to see if you have one of these viruses. Each type of hepatitis is treated different. Knowing which virus you have helps your healthcare provider decide on treatment. Once treatment has begun, additional tests may be used to see how well your treatment is working.
How do I prepare for these tests?
Usually no preparation is needed for these tests.
Talk to your healthcare provider if you have any questions.
How are the tests done?
Having these tests will take just a few minutes. A small amount of blood is taken from a vein in your arm with a needle. The blood is collected in tubes and sent to a lab.
Ask your healthcare provider when and how you will get the result of your test.
What do the test results mean?
Hepatitis blood tests check 2 kinds of things for each virus. Antigen tests check if you have the virus in your blood. Antibody tests check your body’s reaction to the infection.
Hepatitis A tests:
- A positive antigen test and a positive antibody test mean you currently have a hepatitis A infection.
- A negative antigen test and a positive antibody test mean you have had hepatitis in the past.
Hepatitis B tests:
- A positive antigen test and a positive antibody test mean you currently have a hepatitis B infection.
- A negative antigen test with a positive antibody test means you are immune because you have either had hepatitis B in the past or have had shots to protect you against hepatitis.
Another test measures the amount of hepatitis B virus in your blood. It is sometimes called “viral load”. The more virus you have, the greater your risk of serious liver problems.
Hepatitis C tests:
- A positive antibody test means you currently have or have previously had a hepatitis C infection.
Another test is done to measure the amounts of hepatitis C virus in the blood. If these tests stay positive for several months, it may mean that you have a severe form of this infection.
What if my test result is not normal?
Test results are only one part of a larger picture that takes into account your medical history, physical exam, and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about the results and ask questions, such as:
- If you need more tests
- What kind of treatment you might need
- What lifestyle, diet, or other changes you might need to make
Hepatitis A, B, and C Blood Tests: References
Centers for Disease Prevention and Control. Interpretation of Hepatitis B Serologic Test Results. US Dept of Health and Human Services, Centers for Disease Control and Prevention. Adapted from MMWR 2005. Accessed 6/2014 from
http://www.cdc.gov/hepatitis/hbv/pdfs/serologicchartv8.pdf.
http://www.labtestsonline.org/understanding/analytes/hepatitis_c/test.html.
Harrison’s Principles of Internal Medicine, 14th edition, Editor Anthony Fauci MD et al, McGraw-Hill publisher, pgs 1677-1692.
MedlinePlus. Hepatitis viral panel. US Dept of Health and Human Services, National Institutes of Health, National Library of Medicine. 12/2010. Accessed 5/2012 from http://www.nlm.nih.gov/medlineplus/ency/article/003558.htm.