Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Hepatitis is an inflammation of the liver. There are different types of hepatitis. Some are caused by viruses. They include hepatitis A, hepatitis B, and hepatitis C. To diagnose hepatitis, your health care provider will ask you about your medical history and symptoms, do a physical exam, and order blood tests.
There are blood tests for each type of viral hepatitis. Some tests check for antibodies to the virus. Antibodies are blood proteins that your immune system makes in response to the virus. Other blood tests look for parts of the virus, such as proteins or genetic material. Some tests show that you have the infection now. Other tests show that you have had it at some time, or that you have immunity to it.
Doctors use the tests to diagnose hepatitis, and to screen people who are at risk for hepatitis B or C. The risk factors are different for each type. Doctors may also use the tests in people who have hepatitis, to check how contagious they are or to see how well treatment is working.