Skip to Content

Introduction to Sweating Disorders


Shinjita Das

, MD, Harvard Medical School

Last full review/revision Jun 2020| Content last modified Jun 2020

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.

Getting Under the Skin

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

Copyright © 2021 Merck & Co., Inc., known as MSD outside of the US, Kenilworth, New Jersey, USA. All rights reserved. Merck Manual Disclaimer