What Does "AIDS" Mean?

AIDS stands for Acquired Immune Deficiency Syndrome:

Acquired means you can get infected with it. Immune Deficiency means a weakness in the body's system that fights diseases. Syndrome means a group of health problems that make up a disease.

AIDS is caused by a virus called HIV: Human Immunodeficiency Virus. If you get infected with HIV, your body will try to fight the infection. It will make "antibodies," special molecules that are supposed to fight HIV.

When you get a blood test for HIV, the test is really looking for these antibodies. If you have them in your blood, it means that you have HIV infection. People who have the HIV antibodies are called "HIV-Positive."

Being HIV-positive, or having HIV disease, is not the same as having AIDS. Many people are HIV-positive but don't get sick for many years. As HIV disease continues, it slowly wears down the immune system. Viruses, parasites, fungi and bacteria that usually don't cause any problems can make you very sick if your immune system is damaged. These are called "opportunistic infections."

How Do You Get AIDS?

The blood, vaginal fluid, semen, and breast milk of people infected with HIV has enough of the virus in it to infect other people. You can get HIV from anyone who's infected, even if they don't look sick, even if they haven't tested positive (yet). Most people get the HIV virus by:

Having sex with an infected person. Sharing a needle or works with someone who's infected. Being born when the mother is infected, or drinking the breast milk of an infected woman.

Getting a transfusion of infected blood used to be a way people got AIDS, but now the blood supply is screened very carefully and the risk is extremely low.

There are no documented cases of HIV being transmitted by tears or saliva, but it is possible to be infected with HIV through oral sex, especially if you have open sores in your mouth or bleeding gums.