A person with HIV is not necessarily a patient with AIDS. Only when the infection has entered the AIDS stage and the patient has developed various opportunistic infections can he or she be called a patient with AIDS. Otherwise, if a patient is still in the incubation period, he or she can only be called a carrier of AIDS. The average incubation period is about 9 years, with the longest being 15 years. During the incubation period, most patients have no obvious symptoms and can work, live and study as normal. It is only when the patient enters the AIDS stage, when the immune function is extremely low and various pathogenic infections occur, resulting in fever, night sweats, diarrhea, and weight loss of more than 10%, that the patient is called an AIDS patient. After entering the AIDS stage, the survival period of patients is often only 12-18 months.