Excessive or increased sweating is referred to as hyperhidrosis. Hyperhidrosis, a term derived from Greek meaning “too much water,” describes a condition in which there is an unusually high and often uncontrollable production of sweat. It is a disorder characterized by spontaneous, localized excessive sweating, particularly in areas such as the underarms, soles of the feet, and palms of the hands. This sweating exceeds the normal requirements of physiological thermoregulation and reflects an exaggerated response of the sweat glands to normal stimuli.

Hyperhidrosis can be classified into generalized excessive sweating and localized excessive sweating. Most cases involve primary, localized hyperhidrosis of unknown cause. As its causes are not yet fully understood, it is referred to as idiopathic or essential hyperhidrosis. Its intensity is influenced by the amount of the neurotransmitter acetylcholine present in the synaptic cleft. This specific type of hyperhidrosis is treated with injections of botulinum toxin.