There is an old saying that bears much testimony to the sad case of HIV and AIDS. It goes like this: "You don't know what you've got, until you don't have it anymore". The immune system in human beings normally functions without any type of conscious thought having to be generated. HIV (human immunodeficiency virus) is a virus that attacks the tissues in the body that generate the immune systems disease fighters, the white blood cells and lymphocytes that identify and destroy invading pathogens before they can take root and cause irreparable damage to our bodies. People who have HIV develop a disease known as AIDS (acquired immunodeficiency syndrome) where their first line of defense, the immune system is reduced, and in severe cases, knocked out. This opens the body up to all kinds of opportunistic illnesses, such as colds, influenza, bronchitis, inflammation, infection, and the sort. People who die because of AIDS don't die from AIDS; they die from their bodys inability to ward off the common afflictions that usually are little more than an uncomfortable inconvenience.