Introduction to Sweating Disorders

ByShinjita Das, MD, Harvard Medical School
Reviewed/Revised Mar 2024
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    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 3 layers: the epidermis, the dermis, and the fat layer. 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.

    Sweating disorders include

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