Testing for the hepatitis B virus will be different depending on where you live. Sometimes your family doctor will just do a few initial tests and leave further investigations to the specialist if you are found to have hepatitis B. In other situations a variety of tests may be done all at once.
Initial tests
Your doctor will ask a variety of questions about your past medical history, contact with others who may have hepatitis B and other possible risk factors (such as use of needles for tattoos or injecting drugs). They may then examine you for signs of liver disease. If they feel it is needed they may then suggest a blood test. This is known as an HBsAg (hepatitis B surface antigen) test and is the most important test to diagnose hepatitis B. It looks for something called hepatitis B surface antigen or HBsAg which is a part of the outer surface of the hepatitis B virus (it is this antigen that normally triggers your immune system to respond). If the HBsAg test is positive this means that you have the virus in your body. It could be either acute or chronic hepatitis B.1
There are various other tests that your GP may recommend. They will be carried out by healthcare professionals and may include:
- Liver function tests (LFTs): This blood test will measure certain proteins, including enzymes, to check that the liver is working well, and whether there is any inflammation or other damage. The test also looks at levels of proteins made by the liver such as albumin and the blood clotting protein prothrombin.2
- Full blood count: This blood test checks your general health and looks for signs of infection or anaemia.1
- Clotting tests: The liver makes some of the proteins the body needs to make blood clot such as prothrombin, and a test of blood clotting may identify problems with the liver. It is also important to perform these tests before a liver biopsy is done because of the risk of bleeding after a biopsy.3
It may take several days or even weeks to get the results of some of these tests and sometimes your doctor will only contact you if they find something abnormal – make sure you ask your doctor when to expect to hear from them.