[4] Eccrine sweat glands are found in virtually all skin, with the highest density in the palms of the hands, and soles of the feet, and on the head, but much less on the torso and the extremities.

[5][6] They produce sweat, a merocrine secretion which is clear, odorless substance, consisting primarily of water.

Postganglionic sympathetic fibers innervating the cutaneous district can produce either noradrenaline or acetylcholine as neurotransmitters depending on the target structure.

The secretion of eccrine glands is a sterile, dilute electrolyte solution with primary components of bicarbonate, potassium, and sodium chloride (NaCl),[6] and other minor components that may include glucose, pyruvate, lactate, cytokines, immunoglobulins, antimicrobial peptides such as dermcidin, and many others.

The Na+ ions are re-absorbed into the tissue via the epithelial sodium channels (ENaCs) that are located on the apical membrane of the cells that form the eccrine gland ducts (see Fig.

But in these cases, the problem is in the CFTR chloride transporter that is also located on the apical membrane of eccrine gland ducts.