Causes of Excessive Underarm Sweating

Perspiration is the body's natural cooling system. When body temperature rises--due to physical activity or strong emotions, such as anxiety, embarrassment and stress--the nervous system triggers the sweat glands to release a fluid comprised of water, salt and small amounts of other electrolytes. Everyone sweats, but when excessive underarm sweating occurs, this could signal the need for medical evaluation and treatment.

• Antiperspirants are the first line of treatment

When is Underarm Sweating Excessive?

• The Mayo Clinic notes that underarm sweating--and perspiration on other parts of the body--is excessive when the sweat glands produce more sweat than is needed to regulate body temperature. This results in a medical condition called hyperhidrosis. In addition to the underarms, excessive sweating may also be noted on the palms of the hands and soles of the feet. Hyperhidrosis can be the source of great embarrassment and have a negative affect on the sufferer in social and occupational settings.

Generalized Hyperhidrosis

• Generalized, or secondary, hyperhidrosis has an underlying medical cause, states the Mayo Clinic, and usually begins suddenly. Certain medical conditions can cause generalized hyperhydrosis. The National Institutes of Health (NIH) lists some of these as heart disease, anxiety conditions, hyperthyroidism, stroke, anxiety conditions, hot flashes during menopause or difficulty regulating glucose. But generalized hyperhidrosis can also be a side effect of taking certain medications.

Focal Hyperhidrosis

• Focal, or primary, hyperhidrosis has no underlying medical cause. This type of hyperhidrosis affects around 2 to 3 percent of people, notes the National Institutes of Health, although less than 40 percent of them seek medical consultation and treatment. In most cases, focal hyperhidrosis begins before the age of 20. According to the NIH, hyperhidrosis tends to run in families, so there may be a hereditary component.

Other Symptoms

• Focal hyperhidrosis occurs bilaterally--excessive underarm sweating is noted under both arms. Usually, perspiration subsides during sleep. When underarm sweating is excessive, perspiration can noticeably soak through fabric and necessitate a change of clothing.

Treatment Options

• The Mayo Clinic notes that generalized hyperhidrosis is often cured when the medical condition that causes it is addresses or a medication discontinued. However, those with focal hyperhidrosis may require ongoing treatment. According to the International Hyperhidrosis Society (IHS), antiperspirants, such as an over-the-counter product or a stronger formulation prescribed by a doctor, are the first line of treatment for excessive underarm sweating. Excessive underarm sweating is also treated with oral medications (although the IHS notes that this is not an optimal long-term treatment plan), Botox injections, or sometimes with a home treatment method called iontophoresis, which makes use of a battery-operated device that delivers a mild electrical current to the area of the body being treated when immersed in water or through a water-saturated wool pad. Surgical techniques are used to treat excessive underarm sweating only when all other options fail.