Positive reaction of hepatitis B core antibody may be caused by having been infected with hepatitis B, being infected with hepatitis B or suffering from insidious chronic hepatitis B and so on. 1. Infected with hepatitis B: If the patient is positive for hepatitis B core antibody, it means that the body has produced anti-hepatitis B virus antibody. If the surface antigen of hepatitis B is negative at the same time, it generally indicates that the patient has been infected with hepatitis B in the past, but it has been treated well, so the surface antigen is negative, and in general, the patient is not infected at the present time. 2. Being infected by hepatitis B: when hepatitis B core antibody is positive and hepatitis B surface antigen is positive, it means that the virus is replicating in the body and producing antibodies in the body, indicating that the patient is in the period of hepatitis B virus infection. 3. Hidden chronic hepatitis B: hepatitis B core antibody is positive, but its hepatitis B surface antigen test is negative, but the patient’s body has viral infection, because hidden chronic hepatitis B patients are not easy to detect, so the hepatitis B surface antigen test is negative. When patients only have hepatitis B core antibody positive reaction, they should further go to the hospital for further examination and treatment under the guidance of professional doctors.