Patients with HIV do not usually have significant symptoms for 3 months after infection. During this period, the patient is still in the incubation period. Although the virus is continuously replicating, the CD4+ T-lymphocyte count remains at a relatively high level and no opportunistic infection occurs, so there are no corresponding symptoms. When the patient enters the AIDS phase, which often takes about 9 years, the patient will develop a variety of opportunistic infections due to low immune function. Patients may experience fever, night sweats, diarrhea, weight loss of more than 10%, and swollen lymph nodes throughout the body for more than a month due to opportunistic infections. Eventually, the patient may die from opportunistic infections and malignant tumors.