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Doctor K: Excessive sweating can be treated

DEAR DOCTOR K: I sweat heavily, day and night. With summer here, I’m desperate. I’m in my 70s, well past menopause.


Hyperhidrosis is not trivial. Excessive sweating can dampen your social life and interfere with work. Some people with hyperhidrosis sweat through their clothing two or three times a day. Fortunately, there are several ways to treat it.

Why do we need to sweat? Our body tries to keep its inside temperature constant, at around 98.6 degrees F. When, because of exercise or hot weather, we start to heat up, our body needs to lose heat. When we sweat, the evaporation of sweat from our skin causes the loss of heat.

How do we sweat? Sweat is made by little glands under the skin – little sacs that fill with fluid, and then release that fluid through a little pore or channel to spill out on the surface of the skin. The type of sweat glands called eccrine glands are activated by signals from the brain. Those signals travel through nerves to your skin. The nerve endings release a chemical called acetylcholine.

People with hyperhidrosis are overly sensitive to acetylcholine. In response, they produce much more sweat than average. In most cases, excessive sweating isn’t dangerous; it’s simply embarrassing and inconvenient. But that’s reason enough to want to do something about it.

Treatments for hyperhidrosis include the following:

• Topical antiperspirants are effective for underarms as well as hands and feet. Look for a preparation containing an aluminum salt, such as aluminum chloride.

• In iontophoresis, your hands or feet are submerged in lukewarm water for 20 to 30 minutes while a mild electric current is passed through the water. This appears to temporarily block sweat glands.

• Botulinum toxin A (Botox) injections are FDA-approved for underarm hyperhidrosis and are also effective for hands and feet. Multiple injections are required.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.