People with HIV infection cannot be seen from the surface. AIDS is a sexually transmitted disease caused by infection with the human immunodeficiency virus, which disrupts the body’s immune system and results in the appropriate clinical manifestations. After HIV infection, one will probably go through the acute infection phase, the asymptomatic infection phase, the pre-AIDS phase, and the AIDS phase. There are no specific clinical manifestations of HIV infection. In the acute infection period, there are flu-like symptoms, and in the asymptomatic period, there are mostly no conscious symptoms. Symptoms of infection can appear in the pre-AIDS period, such as hairy mucous membrane leukoplakia, oral and vaginal candidiasis, and herpes zoster, none of which are specific. The AIDS phase can lead to systemic tissue and organ involvement, opportunistic infections as well as malignant tumors.