They are ten times smaller than apocrine sweat glands, do not extend as deeply into the dermis, and excrete directly onto the surface of the skin. The proportion of eccrine glands decreases with age.

The clear secretion produced by eccrine sweat glands is termed sweat or sensible perspiration. Sweat is mostly water, but it does contain some electrolytes, since it is derived from blood plasma. The presence of sodium chloride