Acute phase symptoms usually appear within 6 months after infection, but the time of onset of symptoms varies among individuals. In the acute phase, patients with AIDS may have clinical symptoms related to HIV anemia and acute damage to the immune system. Most patients have mild clinical symptoms that last for one to three weeks and then resolve on their own. Fever is the most common clinical manifestation, which may be accompanied by headache, night sweats, nausea, vomiting, diarrhea, sore throat, muscle pain, arthralgia, rash, enlarged lymph nodes, and neurological symptoms. These symptoms usually resolve on their own without treatment, and they are not specific and are similar to those caused by other infectious diseases, so the presence of HIV infection cannot be determined based on these symptoms. To determine whether a person is infected with HIV after a high-risk exposure to the virus, laboratory tests must be performed regularly under the supervision of a doctor.