Sweating is the body's natural cooling mechanism. The nervous system automatically stimulates the sweat glands when the body temperature rises. Sweating also occurs naturally, especially in the palms, when a person is emotionally aroused.
The most common form of hyperhidrosis is called primary (or focal) hyperhidrosis. In this type, the nerves that send signals to the sweat glands become overactive, even without being stimulated by physical activity or a rise in temperature. Stress or emotional arousal exacerbates the problem. This type usually affects the palms, soles, and sometimes the face.
There is no known medical cause for this type of hyperhidrosis. It may have a genetic component, as it sometimes runs in families.
Secondary hyperhidrosis occurs when excessive sweating is caused by an underlying medical condition. It is less common and is more likely to cause sweating all over the body. Conditions that can cause excessive sweating include:
Diabetes
Menopausal hot flashes
Thyroid problems
Low blood sugar
Certain types of cancer
Heart attack
Nervous system disorders
Infections
