Syndromes

In medicine, the term syndrome is the association of several clinically recognizable features, signs, symptoms, phenomena or characteristics which often occur together, so that the presence of one feature alerts the physician to the presence of the others. In recent decades the term has been used outside of medicine to refer to a combination of phenomena seen in association.

The term syndrome derives from the Greek and means literally "run together," as the features do. The term syndrome is most often used when the reason that the features occur together (pathophysiology) has not yet been discovered. A familiar syndrome name often continues to be used even after an underlying cause has been found. Many syndromes are named after the physicians credited with first reporting the association; these are "eponymous" syndromes. Otherwise, disease features or presumed causes, as well as references to geography, history or poetry, can lend their names to syndromes

AIDS, a case study
A recent case study is Acquired Immune Deficiency Syndrome (AIDS), so named as most syndromal immune deficiencies are either inborn or secondary to hematological disease. AIDS was originally termed "Gay Related Immune Disease" (or GRID), a name which was revised as the disease turned out to equally affect heterosexuals. Several years passed after the recognition of AIDS before HIV (human immunodeficiency virus) was first described, finally explaining the hitherto mysterious "syndrome".

SARS (severe acute respiratory syndrome) is an even more recent example of a syndrome that was later explained with the identification of a causative coronavirus.