Sweating is the body’s natural cooling system, and its quantity varies from person to person. Excess sweating, also called hyperhidrosis, is uncontrollable sweating without an external reason (such as physical exercise, anxiety, disease). The condition is common and can affect all parts of the body, but is most often apparent in zones such as armpits, feet, hands, face. The exact reasons for this condition are unclear, but it is possible that it is caused by overactive sweat glands. It could also be caused by an overactive sympathetic nervous system, or be hereditary.