Basic information for topics, such as “What is it?” is available in the About HIV section. Answers to other frequently asked questions (FAQs) specific to HIV and AIDS are in this section.
HIV destroys vital cells of the immune system called CD4+ T cells. AIDS occurs when the body’s immune system has been badly damaged by the virus.
A healthy person has between 500 and 1,600 CD4+ T cells in one cubic millimeter (about 1/50,000 of a teaspoon) of blood. A person with HIV is considered to have progressed to AIDS when they have fewer than 200 CD4+ T cells per cubic millimeter of blood, or when they develop certain opportunistic infections regardless of their CD4+ count.
HIV currently has no cure, but highly effective treatment options can keep HIV under control, both benefiting the person with HIV and preventing transmission of the virus to others. Read more about HIV treatments.