Two tests need to be done to discover if you have hepatitis C. The two tests can often be done from one sample of blood which means you may only need to provide the sample once. Both tests can then be done on your sample at the laboratory. However, some services will perform one test and then call you back for a further blood sample to perform the second test.
A hepatitis C antibody test is the first test undertaken. This is to determine whether you have ever been exposed to the hepatitis C virus. It works by testing for the presence of antibodies to the virus generated by your immune system. If you receive a negative hepatitis C antibody test but have been experiencing symptoms or have been recently exposed to hepatitis C, then you are likely to be advised to have a second test.
It is important to remember that there is a 'window period'. This is the short period of time when your immune system may not have had time to produce antibodies. It usually takes between six and twelve weeks for these antibodies to develop. However, in a few people it can take up to six months. So if you have the test within this window period and the result is negative, it does not necessarily mean that you don't have the virus.
If you receive a positive hepatitis C antibody test it does not necessarily mean you are currently infected. Up to 20% of people clear the virus from their bodies naturally. This is called ‘spontaneous clearance’. Although they have cleared the virus, tests will still show the presence of hepatitis C antibodies. There is a chance that you may have been infected with hepatitis C in the past but you are no longer infected.