What is the difference between HIV and AIDS? My friend is HIV-positive. Someone made the remark that my friend had AIDS, and he seem rather bothered by this and stated that he did not have AIDS, that he had HIV. It was then said that they are both the same -- there is no difference. My friend again stated that there is a difference and was bothered by the reference. Is there a difference? Is there a psychological need for a person who is HIV-positive to separate the two?

T. C.

You have touched on some excellent points. As I have said before on this site, HIV, the human immunodeficiency virus, is the virus that causes AIDS. AIDS, acquired immune deficiency syndrome, is the name given for a variety of disease manifestations caused by HIV infection.

The U.S. Centers for Disease Control in Atlanta, Ga., has compiled a list of all the infections and tumors that doctors use to define AIDS. For example, if a person with HIV develops tuberculosis, he or she is then said to have developed AIDS. The same is true for pneumocystis pneumonia (PCP), cryptococcal meningitis and a CD4 (T-cell) count below 200. This list and the official definition of AIDS are simply standard ways of describing patients with various HIV-related illnesses. (The definition of AIDS is also used by some insurance companies and health programs to define who is disabled and who is not.) To simplify the matter even further, we can say that AIDS is the disease and HIV is the cause of the disease.

Personally, I rarely use the term "AIDS" in my practice. It is frightening to think of oneself as having AIDS. Since it usually takes several years to become ill (develop AIDS) after infection with HIV, most of my patients would rather think of themselves as being infected with a virus than having AIDS, a life-threatening illness. As an analogy, think of the new findings of genes that predispose a person to develop breast cancer. If a woman finds out that she has such a gene, she certainly does not yet have breast cancer. If you told her that she has breast cancer, she would likely correct you, saying, "I probably will develop breast cancer in the future, but for now, I only have the gene." Many of my patients would say, "I probably will develop AIDS in the future, but for now, I only have HIV." It seems a subtle difference to those who are not infected, but -- trust me -- it is an important distinction, and it is one to which I pay close attention in my practice.