Lymph node enlargement during the window period of AIDS is characterized by the follicular metaplasia stage, follicular disappearance stage and so on. 1. Follicular metamorphosis stage: in the early stage of infection, as the virus mainly attacks the lymphatic system, lymphatic hyperplasia is predominant, forming onion skin-like. 2. Follicular metamorphosis: After HIV infection, lymph nodes in the neck, armpits, groin and other parts of the lymph nodes are enlarged; lasts for one to two weeks will generally be symptom-free into the AIDS incubation period. The window period of AIDS refers to the period from HIV infection to the detection of antibodies. With the application of the 4th generation reagent, one month after the window period, it can be clear whether one is infected with HIV or not by antibody test. In the window period of AIDS, you cannot diagnose whether you are infected with HIV by the swelling of lymph nodes. After one month to forty-two days, you can use the colloidal gold reagent of the 4th generation to test or go to the hospital for blood test to avoid the fear of AIDS or missing the best time for treatment.