On a hot day or following vigorous physical activity, the body cools itself by excessive sweating. Excessive sweating, including under the arms, not triggered by heat or activity describes focal hyperhidrosis .Statistics from Medline Plus show that 2 to 3 percent of the population have this condition yet less than 40 percent seek medical advice.
Heat, Physical Activity and Emotions
The body has about 4 million sweat glands, of which 3 million are eccrine sweat glands and the rest are apocrine sweat glands. Eccrine sweat glands function to produce sweat. Apocrine sweat glands are scent glands found in the underarm and urogential areas. Medline Plus states that how much you sweat depends on the number of sweat glands you have. Women have more than men but male sweat glands are more active. Sweating is the body's way of cooling off, especially on a hot day or after a strenuous work out. Cooling off happens as sweat evaporates from the skin's surface removing extra heat. Emotions such as anxiety, anger and fear can also make a person sweat.
Over-stimulation of Sweat Glands
Over-stimulation of the sweat glands by the sympathetic nervous system produces excessive sweating. Referring to the article, "Focal Hyperhidrosis: Diagnosis and Management" by Aamir Haider and Nowell Solish, a survey of 150,000 households in the United States found that most people affected by this condition, actually 51 percent, had excessive sweating in the armpits. Focal hyperhidrosis affects the face, armpits, hands and feet, which are all areas involved in emotional sweating. The eccrine sweat glands are stimulated by the sympathetic nervous system. These two researchers surmised that excessive armpit sweating is a complex malfunction in the sympathetic nervous system.
Genetics
According to Medline Plus, focal hyperhidrosis runs in families. A genetic disposition to excessive sweating may be something that some people are born with and is passed down through the generations. The condition first appears during adolescence but has been reported in the pre-puberty years. Focal hyperhidrosis generally starts after puberty in women, yet there is not established hormonal correlation.
