HIV is a virus that can multiply rapidly in your body. Without treatment, HIV can make your immune system very weak. If this happens, you might get an "opportunistic infection." Common germs cause these diseases. People with healthy immune systems can be exposed to these germs and not get sick. The same germs can cause serious illnesses in people with weak immune systems.
The first medication for HIV was approved in 1987. Now there are many different drugs that can be used to slow down the HIV virus. Most people with HIV disease can now expect to live healthy lives for many years.