Hyperhidrosis is a medical condition in which a person sweats excessively and unpredictably. People with hyperhidrosis may sweat even when the temperature is cool or when they are at rest.
Sweating helps the body stay cool. In most cases, it is perfectly natural. People sweat more in warm temperatures, when they exercise, or in response to situations that make them nervous, angry, embarrassed, or afraid.
Excessive sweating occurs without such triggers. Persons with hyperhidrosis appear to have overactive sweat glands. The uncontrollable sweating can lead to significant discomfort, both physical and emotional.
When excessive sweating affects the hands, feet, and armpits, it is called primary or focal hyperhidrosis. In most cases, no cause can be found. It seems to run in families.