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Medical Term:


Pronunciation: pers'pi-ra'shun


  1. The excretion of fluid by the sweat glands of the skin.
  2. All fluid loss through normal skin, whether by sweat gland secretion or by diffusion through other skin structures.
  3. The hypotonic fluid excreted by the sweat glands; it consists of water containing sodium chloride and phosphate, urea, ammonia, ethereal sulfates, creatinine, fats, and other waste products; the average daily quantity is estimated at about 1500 g.

Synonym(s): diaphoresis, sudation, sweating

[L. per-spiro, pp. -atus, to breathe everywhere]

See Also: sweat

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