Excessive sweating is a health condition in which a person sweats more than usual. If you sweat excessively, it can be very uncomfortable and interfere with daily activities. Excessively sweaty feet are especially bothersome because of the moisture they produce on your carpet or flooring. Excessive sweating can also lead to decreased performance at work or school, social embarrassment and even depression if not treated correctly. There are several medical conditions that cause excessive sweating but most commonly this is due to disorders of the parathyroid glands (hyperparathyroidism). The parathyroids are two small glands located near your kidneys that regulate calcium levels in your body. When there is an overactive parathyroid gland, there will be too much calcium released into the bloodstream which causes excessive perspiration (sweating) on the skin surface as well as dry mouth, constipation and headache (these effects may occur before any physical signs of hyperparathyroidism appear).