HIV stands for human immunodeficiency virus. It is a virus that weakens the immune system. It attacks and takes over the immune cells, using them to reproduce itself and go on to infect other cells. It is primarily transmitted in blood, semen and vaginal fluids via condomless sex or sharing injecting equipment. HIV is the virus that can cause AIDS.
Acquired immune deficiency syndrome (AIDS) is not a single disease. It is a diagnosis that results from a spectrum of conditions that can occur when a person’s immune system is seriously damaged after years of attack by HIV. The terms HIV and AIDS are not interchangeable, but it is possible to move in and out of an AIDS diagnosis. It is important to remember that a person who is infected with HIV does not necessarily have AIDS. However, all people with AIDS have HIV.
HIV damages the body’s immune system and renders the body vulnerable to other diseases and infections – its symptoms are most commonly similar to those of any chronic viral infection. During advanced stages of HIV infection, a person may develop any of a number of opportunistic infections considered to be AIDS defining illnesses.