Human immunodeficiency virus, or HIV, is a complex virus that can lead to the disease AIDS if left untreated. HIV is a virus that the human body cannot get rid of completely.

There are many myths about how HIV is transmitted. The most common way to transmit HIV is through sexual behaviors and needle or syringe use. Certain body fluids — blood, semen, rectal fluids, vaginal fluids, and breast milk — can transmit HIV. Sexual activity is the No. 1 cause for the spread of HIV.