However, studies have confirmed that HIV infection comes first before AIDS. HIV is a retrovirus; it belongs to the viral family Retroviridae. Viruses in this family are enveloped viruses possessing an RNA genome and replicate via a DNA intermediate. A dramatic reduction in the vitality of the human immune system is the primary result of an infection of HIV. It directly and indirectly destroys marcophages, dendric cells, and CD4+ T cells of the body. These elements are very essential in the proper functioning of the human immune system. Once the immune system is attacked by HIV, various infections and diseases start to manifest; the collection of these diseases is what we call AIDS. The most common diseases caused by HIV are acute renal failure, cardiomyopathy, dementia, and encephalopathy. HIV also attack the brain, heart, and kidney. Many of the problems faced by people infected with HIV result from the failure of the immune system to protect the body from opportunistic infections and cancers.

What immediately follows after an exposure to sources of HIV is the development of acute infections. The stage of acute infections or primary infections is the period when the virus replicates inside the body and causes flu-like infections such as fever, malaise, myalgia, pharyngitis, lymphadenopathy, and fever. Since flu-like infections such as these are very common among people with flu, these symptoms of a possible HIV infection are mostly being dismissed as mere cases of flu. In most cases, the infection is only realized to be an HIV infection if the case has already turned into an AIDS disease. The second stage of HIV infection is the chronic asymptomatic infection stage. This stage is chararcterized by a long duration of infection, an average of 8 to 10 years, without symptoms. Infections on this stage range from unexplained chronic diarrhea, persistent fever, severe weight loss, oral hairy leukoplakia, candidiasis, and severe bacterial infections including pulmonary tuberculosis. It is at stage two that the body's CD4+ T Cells count starts to drop below the 500 count. When the CD4+ T Cells count reaches below 200 count, the HIV infection then leads to AIDS.