Sweating Disorders (Hyperhidrosis)

Sweating, or perspiring, helps remove some of the body's wastes through the pores of the skin. It also aids in regulating the body's temperature by cooling through evaporation, and it provides an acidic coating that controls the growth of skin bacteria.

Two types of glands -- apocrine and eccrine -- produce sweat, but their production differs. Apocrine glands, which enlarge as puberty approaches, are located in the armpits, where they are the most active, as well as selected areas of skin on the trunk, face, and scalp. They exude a scant amount of milky perspiration that contains proteins, carbohydrates, and lipids, which give it a somewhat unpleasant smell as these substances are broken down by bacteria. Apocrine sweat is thought to broadcast sexual signals through the odor of a group of chemicals known as pheromones. Nothing inhibits the production of this sweat, but deodorants diminish its smell.

The wetness associated with sweating is produced by the approximately three million eccrine glands, located all over the body except in the ear canal. Eccrine sweat is mostly water, plus small amounts of potassium, salt, urea, and a few other ingredients. It is sterile and odorless, except when transmitting the smells of onion, garlic, and similar foods.

Under normal circumstances, the eccrine glands produce about one quart of sweat every day, but this amount varies from person to person and depends on age, sex, race, and sensitivity to heat. From time to time, an individual may produce up to 10 quarts of sweat in a day, due to heat, heavy physical activity, or undue emotional turmoil; this is still considered normal.

A variety of circumstances, ranging from eating highly spiced food to having a heart attack, may produce abnormally heavy sweating, or hyperhidrosis, but stress is the most common cause. Technically referred to as emotional hyperhidrosis, this type of chronic sweating appears to run in families and is most obvious in the armpits or on the palms and soles. It begins during childhood and is more prevalent in men than in women.

Diagnostic Studies and Procedures

A doctor who is consulted about heavy sweating will take into account the individuals sex, age, and medical history. A diagnosis of emotional hyperhidrosis often entails a process of eliminating possible medical causes. A physical examination is conducted, and blood and urine studies, X-rays, and other tests may be ordered.

Medical Treatments

If excessive sweating is a manifestation of an underlying disorder, treatment of that condition often solves the problem.

For excessive underarm sweating, the most effective medication is Drysol, a 20 percent solution of aluminum chloride (hexahydrate) in ethyl alcohol. At bedtime, it is applied under the arms to completely dry skin and then covered with a thin layer of polyethylene (plastic wrap). In the morning, the wrap is removed and the area is bathed. After application on two or three consecutive nights, Drysol usually need not be used more than once or twice a week.

Medications with an anticholinergic action, for example, drugs prescribed to calm excessive bowel spasms, may be prescribed as a short-term solution for heavy sweating because of their drying effect. In especially troublesome cases, surgical removal of overactive sweat glands may be considered. This may entail removing a strip of underarm skin or severing some of the nerves that control areas rich in sweat glands. Such operations carry a risk of infection and loss of sensation and so are reserved for the most refractory cases.

Alternative Therapies

Biofeedback training. A person who sweats excessively when under stress may leam how to control the process by using electronic monitors to alter normally automatic body responses.

Relaxation techniques. The body's response to stress is controlled by the hypothalamus, a pan of the brain that also regulates the sweating process. Thus, stress management through meditation and breathing exercises can help reduce heavy sweating.

Self-Treatment

Most sweating problems can be controlled through common sense and self-care. If you are especially sensitive to heat, wear light, layered clothing that is easy to remove as needed and use a small hand fan. To reduce night sweats, steep in a cool room, use a light covering, and wear light, cotton nightclothes.

To control sweaty feet:

• Use a medicated foot powder to absorb moisture.
• Choose footwear made of leather or fabric. Wear sandals when possible.
• Wear white cotton socks and change them whenever necessary.

To reduce underarm sweating:

• Use a deodorant with antiperspirant action.
• Select a cream or roll-on product instead of an aerosol spray, which may contain harmful propellants.
• If your skin won't tolerate any antiperspirant or deodorant, try using a cream or ointment containing the antibiotic neosporin, or experiment with various antibacterial soaps.

Other Causes of Heavy Sweating

Recurring episodes of heavy sweating may signal an underlying medical condition; possibilities include certain cancers, AIDS, malaria and other infections, and an overactive thyroid and other hormonal disturbances. Transient heavy sweating may be prompted by fever, medications, and withdrawal from various addictive drugs, including alcohol and narcotics.