Acetylcholine acts as a potent stimulator for sweat secretion, which is released by sympathetic nerves. β-adrenoceptors are found in adipocytes as well as apocrine glands, and these receptors may mediate lipid secretion from apocrine glands for sweat secretion. The activation of β-adrenoceptors could increase sweat secretion through opening of Ca channels to elevate intracellular Ca concentration. Ca and cyclic adenosine monophosphate play a part in the secretion of lipids and proteins from apocrine glands for sweat secretion. The translocation of aquaporin 5 plays an important role in sweat secretion from eccrine glands. Dysfunction of the ANS, especially the sympathetic nervous system, may cause sweating disorders, such as hypohidrosis and hyperhidrosis.