If the level of hepatitis B DNA in the patient’s blood is less than the lower limit of detection, the patient is considered negative, probably because the virus has not replicated significantly in the patient’s body after infection, or the infection is not yet present, or the infection is in the window phase. If the amount of hepatitis B DNA in the patient’s specimen is greater than the lower limit of detection, i.e. positive, the patient is definitely infected with the hepatitis B virus. If the amount of hepatitis B virus is high, reaching 10^4 IU/ml, 10^5 IU/ml or even 10^8 IU/ml at the highest level, it means that the hepatitis B virus in the patient’s body is now actively replicating, and the need for anti-hepatitis B virus treatment should be decided in conjunction with clinical manifestations and other test results.