Clinical symptoms do not appear immediately after infection with HIV, but there is a window period of 2-4 weeks after infection, during which there are no clinical symptoms. 2-4 weeks later, the viremia of HIV infection and symptoms of acute damage to the immune system will appear, such as fever, malaise, anorexia, night sweats, weakness, nausea, vomiting, diarrhea, joint pains, skin rashes, and swollen lymph nodes, etc. Swollen lymph nodes appear in the neck, armpits, groin, and inguinal area. Lymph nodes appear in the neck, armpits, and groin. The enlarged lymph nodes can be larger than one centimeter in diameter, movable and without pressure pain, and at this time, the CD4+ T lymphocytes have decreased significantly. After 1-3 weeks, the above clinical symptoms will gradually resolve and the CD4+ T-lymphocytes will return to the normal level, after which the patient will enter the incubation period of AIDS.