The first physical signs of HIV are very similar to those of the flu, according to the Mayo Clinic. Symptoms may include fever, headache, fatigue and joint pain, along with diarrhea and a red, nonitchy rash.
HIV infection has three stages, according to WebMD. The first stage usually occurs a few weeks after exposure, when the body begins fighting the initial infection. This is when the flu-like symptoms appear. These symptoms generally last for one to two weeks, and then disappear for years — the second stage. According to Health.com however, only 40 to 90 percent of infected individuals experience these symptoms at all, and so may have no idea they've been infected until much later. This is why testing is so important if there has been any risk of exposure.
Medication can prevent the disease from taking hold, but it must be administered within 72 hours of infection, notes WebMD. Tests can reveal the presence of both the HIV antigen and HIV antibodies.
It's not until the third stage of HIV infection, which may not be until for another 10 years, that further physical symptoms appear. At that time, signs and symptoms may include the same flu-like symptoms as in the first stage, as well as swollen lymph nodes, fever and night sweats, purplish spots and unexplained bruising, and unexplained weight loss, states WebMD.