Hyperhidrosis can either be generalized or localized to specific parts of the body. Hands, feet, armpits, and the groin area are among the most active regions of perspiration due to the relatively high concentration of sweat glands. When excessive sweating is localized it is referred to as primary or focal hyperhidrosis. Generalized or secondary hyperhidrosis usually involves the body as a whole and is the result of an underlying condition.
Hyperhidrosis can also be classified depending by onset, either congenital or acquired. Primary or focal hyperhidrosis is found to start during adolescence or even before and seems to be inherited as anautosomal dominant genetic trait. Primary or focal hyperhidrosis must be distinguished from secondary hyperhidrosis, which can start at any point in life. The latter form may be due to a disorder of the thyroidor pituitary glands, diabetes mellitus, tumors, gout, menopause, certain drugs, or mercury poisoning.
Alternatively, hyperhidrosis may be classified according to the amount of skin affected and its possible causes.