HIV is the virus that causes AIDS. Most people who have HIV have no symptoms at all, but can still give the virus to other people. On average, it takes 10 years for HIV to develop AIDS. AIDS is a serious condition in which the body's ability to resist getting sick is seriously weakened. Once a person develops AIDS, mild diseases like colds and flu can lead to death. A person with AIDS is also very likely to get other, less common diseases like tuberculosis.
HIV Molecular Immunology 2002, Diane Publishing, ISBN 1428918132