Condition: AIDS (Acquired Immune Deficiency Syndrome)

AIDS is an infectious disorder that suppresses the normal function of the immune system. It is caused by the human immunodeficiency virus (HIV), which destroys the body's ability to fight infections. Specific cells of the immune system that are responsible for the proper response to infections (T cells) are destroyed by this virus. Characteristically a person infected with HIV initially experiences no symptoms for a variable period of time. This may be followed by the development of persistent generalized swelling of the lymph nodes (AIDS-related lymphadenopathy). Eventually most patients infected with HIV experience a syndrome of symptoms that includes excessive fatigue, weight loss, and/or skin rashes.

The later stages of HIV infection are characterized by the progressive depression of T cells and repeated infections that can even occur during a course of antibiotic therapy for another infection (superinfections). People with AIDS are particularly vulnerable to "opportunistic infections" from bacteria that other people normally fight off. Pneumocystis carinii, which causes severe inflammation of the lungs (pneumonia), is a common infection that effects people with AIDS. Cancers (malignant neoplasms), and a wide variety of neurological abnormalities, most notably the AIDS dementia complex, may also occur. These neurological symptoms when of HIV infects the nervous system.