Tests and diagnosis
of hepatitis A
Hepatitis A can be diagnosed using blood tests. You will probably have two tests. But these are often both done using the same sample.
The information on this page is for:
- Adults with hepatitis A or suspected Hepatitis A
- Family, friends, carers, and healthcare professionals.
On this page:
Antibody test
This test will look for antibodies against hepatitis A in your blood. When a new virus gets into your body, your immune system starts to try and fight it off. One of the things it does is make antibodies that can stick to the virus and help your body to clear it. It can take a few days for the antibodies to be made. So if you have an antibody test straight after picking up the virus there might not be enough antibodies for the test to work.
After you have got rid of the hepatitis A virus, you will carry on having antibodies in your blood. But they will be a different type. The antibody test does not look for this type of antibody. so the antibody test will only be positive if you have the virus at the time of the test.
PCR test
A PCR test can look for tiny amounts of the virus’s RNA. This is the genetic instructions that the virus uses to make copies of itself. You will only have the virus RNA in your blood if you currently have the virus.
As well as tests for hepatitis A, you might have blood tests for other types of viral hepatitis or HIV. And blood tests to check on your liver health.
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This content was last reviewed: June 2026
Our expert reviewers:
We would like to thank everyone who helped with creating and reviewing this page. Including Dr Jay Patel, Consultant hepatologist, Bedfordshire hospitals NHS trust, Kathryn Jack, Lead nurse for research and innovation, Nottingham university hospitals NHS trust, Dr. Ahmed Elsharkawy, Consultant transplant hepatologist. And all our patient reviewers.
Find out how we make our patient information.
Everyone’s experience of liver disease will be different. Always talk to your specialist medical team for personal advice.
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