In dermatology, the window period refers to the time from infection to antibody positivity, which is related to the individual’s immune status and testing methods. After the HIV virus enters the body, it can start to multiply in 1-2 weeks, and the core antigen of the virus can stimulate the body to produce relevant antibodies. However, in some patients, antibodies can remain negative for up to 2-3 months, and because of the limitations of previous testing methods, the “window period” was 3 months in the old version of the data. With newer testing reagents, most patients can determine if they are infected in 4-8 weeks; if the test is for viral antigens, the “window period” can even be shortened to 1-2 weeks. It is recommended that people who have been infected through unclean sex, unsafe intravenous injections or blood transfusions should seek prompt medical attention from an infectious disease clinic or STD clinic to determine if they are infected. If diagnosed, please follow medical advice for early and standardized treatment.