Description
Hepatitis B surface antigen (HBsAg) is a blood test ordered to determine if someone is infected with the hepatitis B virus. If it is found, along with specific antibodies, it means the person has a hepatitis B infection. If your blood is positive for HBsAg, it means you are infectious for the virus and can pass it to other people through your blood or body fluids.
Precaution
No specific precaution required for this test.