Hyperhidrosis is a condition marked by excessive sweating that goes beyond what is necessary to regulate normal body temperature. This condition involves the overproduction of sweat by the eccrine sweat glands.

Medically, hyperhidrosis is defined as sweat production exceeding 100 mg per cm² per minute. Clinically, it is described more subjectively, referring to sweating that is so excessive it causes discomfort and interferes with daily activities.

Sweat gland activity varies throughout the day, reaching its lowest levels at night and peaking during physical exercise, psychological stress, psychophysical stress, and heat exposure.

Several factors influence skin humidity. The rate of evaporation plays a significant role and is markedly reduced in humid climates or when the sweating area is covered, such as by wearing closed shoes.