Feb 5, - While it's impossible to look at someone and know whether they have HIV, the majority of people will have some symptoms about three weeks. May 15, - Symptoms can include: Rapid weight loss. Recurring fever or profuse night sweats. Extreme and unexplained tiredness. Prolonged swelling of the lymph glands in the armpits, groin, or neck. Diarrhea that lasts for more than a week. Sores of the mouth, anus, or genitals. Pneumonia.