HIV (human immunodeficiency virus) is a virus that attacks the body’s immune system. If HIV is not treated, it can lead to AIDS (acquired immunodeficiency syndrome). Learning the basics about HIV can keep you healthy and prevent HIV transmission.

What do the letters in AIDS mean?

If left untreated, HIV can lead to the disease AIDS (acquired immunodeficiency syndrome).

What can cause AIDS?

Human immunodeficiency virus (HIV) is the virus, or germ, that causes acquired immune deficiency syndrome (AIDS). The virus weakens a person’s ability to fight infections and cancer by infecting and killing CD4 cells (also called T cells). Having HIV does not always mean you have AIDS.