Physical examination can detect AIDS, but there is a premise, not a window period. Window period refers to the patient infected with AIDS, and the time when antibodies appear in the body after HIV infection is called window period. The window period is considered to be 4-8 weeks, and some books say it is about 5 weeks. The length of time can only be approximate, not very accurate. Some books last for 4-8 weeks, and some books last for about 5 weeks, so antibodies are easy to appear. Clinically, you can do blood tests and check HIV antibody detection. Note that it is not an antigen, but an antibody test. If there is no window period before the window period, it cannot be detected during the physical examination. Relatively speaking, the interval of several months can basically be ruled out. The longest time is 2 months, 4-8 weeks. After the window period, most of the absolute 98% can still be found and found out.