Definition and Classification of Hyperhidrosis and Hand Sweat Hyperhidrosis is a state of hypersecretion by the sweat glands of the body, a functional disorder in which the exocrine glands overproduce. Generalized hyperhidrosis can be divided into generalized hyperhidrosis and localized hyperhidrosis. Generalized hyperhidrosis is often secondary to some neuroendocrine and other systemic diseases. Localized hyperhidrosis can be divided into primary and secondary. Secondary hyperhidrosis is often caused by local inflammation or injury affecting the vegetative nervous system. Primary localized hyperhidrosis is hyperhidrosis in a narrow sense, with no obvious organic etiology. Sweating is most common in the palms of the hands, soles of the feet, and armpits, and less common in the face and perineum, while it is rare in other parts of the body. Hand sweating is one of the manifestations of primary localized hyperhidrosis, which is often combined with increased axillary and foot sweating, mainly because of the high density of exocrine sweat glands in the palms of the hands, soles of the feet and armpits.