Everyone's glands are on overdrive in the heat or during a tough workout, but some four million women have a condition called hyperhidrosis, which causes them to perspire up to five times more than average, says DeeAnna Glaser, M.D., professor of dermatology at St. Louis School of Medicine. This condition usually affects one specific area of the body, such as the underarms, hands, face, feet, or groin. Attacks are sudden and random; sufferers never know when they'll wind up with drenched hands or a wet blouse.
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In the majority of cases, your genes are to blame: Hyperhidrosis is typically a hereditary disorder that affects the nervous system. Most sufferers develop the condition as kids or teens. "The brain sends abnormal signals to the glands telling them to start sweating," says Glaser. But in cases of adult-onset hyperhidrosis, the cause is often a medical condition or a prescription drug, like the antidepressant fluoxetine or the sleeping pill eszopiclone. Both may trigger excessive sweating.
What to do about excessive sweating
Have a mild case? Try applying an antiperspirant, like Secret Clinical Strength ($8.29; drugstore.com), in the morning and at night. (If feet or hands are a problem, you can apply antiperspirant to them, too.) And be sure to wear breathable fabrics, like cotton, whenever possible.
For more persistent cases, a dermatologist can prescribe an extra strong antiperspirant or an oral medication that dries out sweat glands. One of the most effective solutions, however, is Botox, injections of which deactivate sweat glands by temporarily immobilizing them. The effect lasts seven months or so and costs about $1,000 for each affected area.
Another treatment for hands and feet, called iontophoresis, involves soaking for 20 minutes a week in a tray of water that's charged with a very mild electrical current. You can find over-the-counter versions of iontophoresis, but the treatment has been shown in studies to be 83 percent effective when done under a doctor's guidance.