HIV (human immunodeficiency virus) is a virus that attacks the immune system. AIDS (acquired immune deficiency syndrome) happens after someone has had HIV for many years. In AIDS, the immune system is severely weakened. People with AIDS get serious infections and health problems.
HIV spreads when infected blood, semen ("cum") or vaginal fluids enter the body. Because symptoms can be mild at first, people with HIV might not know they're infected. They can spread HIV to others without knowing it.
HIV can spread:
HIV also can pass from mother to child during pregnancy, childbirth, or breastfeeding.
HIV does not spread through:
The best way to protect yourself from HIV is to not have sex (vaginal, oral, or anal) and not share needles.
If you decide to have sex, reduce your risk of getting HIV by:
Understanding how HIV spreads can help you make safer choices about sex. Talk to your doctor if you have any questions about HIV and if you want to get tested.
Reviewed by: Robyn R. Miller, MD
Date Reviewed: Oct 1, 2018