Sweat is made by sweat glands in the skin and carried to the skin’s surface by ducts.
Getting Under the Skin
The skin has three layers. Beneath the surface of the skin are nerves, nerve endings, glands, hair follicles, and blood vessels. Sweat is produced by glands in the dermis and reaches the surface of the skin through tiny ducts.
As sweat wets the skin and evaporates, it helps keep the body cool. Thus, people normally sweat more when it is warm. They also sweat when they are nervous, under stress, or have a fever.
Sweat is composed mostly of water, but it also contains salt (mostly sodium chloride) and other chemicals. When a person sweats a lot, the lost salt and water must be replaced.
Disorders of sweating include those of
Variations in the amount of sweat produced (hypohidrosis Diminished Sweating Some people sweat too little (a condition called hypohidrosis). (See also Introduction to Sweating Disorders.) Diminished sweating is usually limited to a specific area of the body. It can be... read more [diminished sweating] and hyperhidrosis Excessive Sweating People with excessive sweating (hyperhidrosis) sweat profusely, and some sweat almost constantly. Excessive sweating usually has no clear cause but is sometimes caused by infections, metabolic... read more [excessive sweating])