There are no exact clinical statistics on how long it will take for the fourth item to turn negative after a 245-positive Hepatitis B test. The test for hepatitis B is usually a blood test for hepatitis B penta, hepatitis B 245 positive refers to positive hepatitis B surface antibody, hepatitis B e antibody and hepatitis B core antibody, which indicates that the body has been infected with hepatitis B virus and now the body has produced protective antibodies against the hepatitis B virus. With the extension of time, the fourth item can gradually change to negative. Clinically, the significance of hepatitis B 245 positive and 25 positive is not much different, both of them represent that the body has been infected with hepatitis B virus and now it has developed resistance to hepatitis B virus, therefore, there is no need to investigate too much when the fourth item can be turned into a negative one, and no special treatment is needed in general.