What does HIV stand for?
HIV stands for the "human immunodeficiency virus." In other words, it is a virus that infects human being and leads to problems with their immune system. The immune system is the body's system for fighting disease.
AIDS and HIV
Understanding what it means to be HIV positive is relatively simple -- either you are infected with the virus or you aren't -- but how do you understand AIDS? AIDS, which stands for "Acquired Immune Deficiency Syndrome" is a way of describing a whole group of symptoms and diseases associated with the damage HIV does to the immune system. As an HIV infection progresses, there is ongoing damage to immune defense cells and the body becomes increasingly less able to fight off infection. This means that individuals with advanced HIV disease are susceptible to infections that don't show up in people with healthy immune systems. They are called opportunistic infections because they take advantage of the weakened ability of an HIV positive individual to fight off disease. The difference between AIDS and HIV is that a person is said to have AIDS, as opposed to simply being HIV positive, when either the numbers of specific types of cells in their immune system drop below a certain level or when they develop one of a specific group of opportunistic infections.
It is important to know that a person can live with HIV for many years without developing AIDS or any symptoms of HIV infection. This is why it is important to be regularly tested for the virus. Even if a person does not know they are infected, however, they can still transmit the virus to other people through unprotected sex and other risky behaviors that directly expose other people to their blood, semen, breast milk, and other potentially infectious bodily fluids. HIV is not spread through casual contact.