Excessive sweating, also called hyperhidrosis, most often begins to manifest during adolescence, hormonal changes, menopause, pregnancy as well as cases where the afflicted person suffers from excessive sweating from a very early age. As far as what causes excessive sweating, doctors are still unable to reliably determine that. However, what they know for sure is that it is an inherited disease that is transmitted from some family members onto their descendents. It is probably caused by a failure of nerve impulses transmitted from the brain to the sweat glands. These nerve impulses instruct the sweat glands about the need to start the process of heavy sweating, even if the body does not need it.
The very controversial operation called thoracic or lumbar sympathectomy is also based on this principle. This is an operation where the surgeon removes the nerve clusters (sympathetic), via which these nerve impulses are transmitted, through small holes in the armpit or groin. Sweating ceases after such an operation, but according to available information, it appears elsewhere on the body to an equally large extent. This operation cannot in good conscience be recommended to anyone.