This test looks for antibodies called IgM in your blood. The test is used to find out whether you are actively infected with the hepatitis B virus (HBV).
HBV has a central core and a surrounding envelope. Your immune system makes IgM antibodies to the core of HBV during the active stage of infection. Hepatitis B core IgM antibodies begin to appear in your blood several weeks after you are first infected with HBV. People who have had the hepatitis B vaccine will not have the core antibody in their blood.
HBV is one of 5 hepatitis viruses. The others are hepatitis A, C, D, and E. Most hepatitis infections are caused by these 5 viruses. HBV is spread through blood, seminal fluid, and vaginal secretions. It can take 60 to 150 days to develop symptoms of hepatitis B after you become infected. The virus causes an infection in the liver. In most cases, this virus clears up on its own within 6 months. But in a small portion of adults and a larger portion of children, the virus does not go away. This is especially true for newborns. This is called having a chronic infection. It may lead to liver cell damage; scarring, or cirrhosis; or liver cancer.
Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore.
The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
Normal results are negative or nonreactive, meaning that no hepatitis B core IgM antibodies were found.