A positive antigen indicates an infection with a certain pathogen, which needs to be determined differently depending on the specific test. Positive hepatitis B surface antigen indicates infection with the hepatitis B virus. Positive surface antigen indicates that the body may be infected with a particular virus, which can be identified by testing for nucleic acids. Antigen tests can also be used to detect fungi, such as the new Cryptococcus podoconiosis antigen test, which is positive for cryptococcal infection. Positive antigens need to be based on the test items to determine the relevant diseases, and then comprehensive treatment, it is recommended to go to the specialist under the guidance of the doctor.