Most HIV-infected people have no symptoms at first, just like healthy people, so they don't know when they were infected. Importantly, these asymptomatic HIV carriers are the main source of infection. Generally, it lasts for several months to 10 years or more. With the gradual decline of immune function, symptoms gradually began to appear. In the early stage of AIDS, AIDS patients show systemic lymphadenopathy, which is common in neck, armpit and groin. Enlarged lymph nodes are mostly symmetrical, characterized by hardness and non-adhesion, no tenderness and fluctuation. A few patients may have mild anemia. But there are no obvious other symptoms. There is also a related syndrome. Various symptoms appear gradually and become more and more serious.