Hyperhidrosis: what is it and why does it occur?

Hyperhidrosis is excessive sweating in response to heat or emotional stimuli beyond physiologic need. The ailment is not new and has been described in the literature dating back several centuries. It can be classified as either primary or secondary based on its etiology. Mechanisms that cause excessive sweating can be traced to the sympathetic nervous system, part of the autonomic nervous system. It has been speculated that the primary abnormality is central, and that the hypothalamic sweat center that controls the palms, axillae, and soles is distinct in hyperhidrosis individuals.