Clinical symptoms do not usually appear after three days of HIV infection, but usually 2-4 weeks after the initial HIV infection. The clinical manifestations are mainly visible as symptoms caused by viraemia and acute damage to the immune system. Most patients have relatively mild clinical symptoms that last 1-3 weeks and then resolve. Fever is the most common symptom at this time, accompanied by sore throat, night sweats, nausea, vomiting, diarrhea, rash, joint pain, swollen lymph nodes, and neurological symptoms. Rapidly progressing patients may develop severe infection, or central nervous system signs and symptoms, and related illnesses during this period. The above manifestations can also be called the acute phase of HIV infection. Patients may go from the acute phase to the asymptomatic phase, or go directly to the asymptomatic phase without obvious acute phase symptoms.