How to Stop Excessive Sweating: Causes and Treatment Options

Summer is the season of swimming, sunbathing — and sweating. As the heat index climbs, our bodies work hard to keep us cool.

“When we become hot, a part of our brain called the hypothalamus signals to little nerves in the skin to tell the sweat gland to produce sweat,” said Dr. Whitney Bowe, a dermatologist in New York City. The liquid then cools us when it evaporates.

But while sweating is helpful for cooling us down, few people enjoy having smelly underarms, stinky feet and clothes stuck to their back and groin. And some people sweat excessively no matter the time of year, and in the absence of typical triggers like heat and physical activity.

Here’s why some of us get extra swampy, and a few methods to cut down on chronic sweating.

Why Some People Are Prone to Perspire

People can sweat more when they have infections, take medications (such as certain antidepressants) or go through perimenopause or menopause, among other causes, Dr. Bowe said.

Others may have a condition known as hyperhidrosis. With this disorder, sweating is often spontaneous and “unrelated to triggers like stress, emotion, exercise and environmental triggers like heat,” said Dr. Mark Ferguson, a thoracic surgeon who treats excessive sweating at UChicago Medicine.

About 5 percent of Americans are believed to have hyperhidrosis. It’s unclear what causes it, but it can run in families. People with hyperhidrosis may sweat excessively around their armpits, hands, feet, scalp or any combination of those body parts, Dr. Ferguson said. Typically, the condition arises either in infancy or during puberty.

For some people with hyperhidrosis, sweating can be so intense that they must change clothes multiple times a day. If their hands sweat, they may have trouble using touch screens, computer mice and steering wheels unless they wear heavy gloves, Dr. Ferguson said.

If their feet sweat, he said, “you can imagine how quickly they go through a pair of shoes, because they’re constantly wet and start to get smelly and start to fall apart.”

Some people sweat so much that it significantly affects their daily lives. “They don’t want to go out anymore,” Dr. Ferguson said.

What Can Help

For people who sweat a lot, Dr. Bowe recommends loose, moisture-wicking clothing. Many athletic brands offer fast-drying layers and outerwear. Numi, a women’s clothing company based in Canada, sells undershirts with sweat-absorbent underarm pads. Mizzen+Main makes sweat-wicking dress shirts for men. It may also help to spend time in well-ventilated, air-conditioned spaces, Dr. Bowe added.

Antiperspirants can also reduce sweating, Dr. Bowe said. These topical treatments are typically made of aluminum compounds that “plug the pores of the sweat glands and prevent sweat from coming out,” said Dr. Lyall Gorenstein, a thoracic surgeon and the surgical director of the Center for Hyperhidrosis at Columbia University Medical Center. (Deodorants are different from antiperspirants: They do not affect sweat production, but can help reduce any accompanying odor.)

Antiperspirants made of up to 15 percent aluminum chloride are sold over the counter, but doctors can also prescribe stronger prescription formulations, Dr. Gorenstein said. These products can be used not just on the underarms, but also on the hands, face and feet.

“If you choose to wear antiperspirant, I recommend applying it at night before you go to bed, rather than in the morning after your shower,” Dr. Bowe said. “Antiperspirant is more effective when it is applied to dry skin rather than damp skin.”

Iontophoresis is an at-home treatment that can also reduce hand, foot and underarm sweat, Dr. Gorenstein said, and it is sometimes covered by health insurance. After soaking the affected skin in water, patients use a small device to produce an electrical current that blocks their sweat glands. The procedure typically has to be done three times in the first few weeks to see initial results, and then once a week to maintain them. Some medical device suppliers may require a prescription for the purchase of an iontophoresis device in the United States.

In-Office Treatments

If you’re up for a series of visits to the doctor’s office, another treatment that can reduce underarm and hand sweat is Botox, which prevents the brain chemical that initiates sweating from activating the sweat glands, Dr. Gorenstein said. Botox is sometimes covered by health insurance. Its effects typically wear off after four to six months around the armpits, and two to three months in the hands, Dr. Gorenstein said. People can also become resistant to the effects of Botox after a few treatments, added Dr. Ferguson of UChicago Medicine.

A treatment called miraDry can also be used to reduce underarm sweat in particular. After doctors have numbed the skin with lidocaine, they use a device to apply heat to the area to destroy its sweat glands. Often, patients see results after one treatment, but two or three treatments may be required, Dr. Bowe said. MiraDry is typically not covered by health insurance and can cost several thousand dollars.

Minor outpatient surgery, called endoscopic thoracic sympathectomy, is usually a last resort, but it can effectively reduce sweating that affects specific body parts, especially the hands, Dr. Ferguson said. During the surgery, doctors make small incisions under the arm and then either cut, clamp or excise nerves that stimulate sweat glands.

“It’s a very effective therapy — I would say 99 percent effective in eliminating bothersome hands sweating,” Dr. Ferguson said. Sometimes, however, people sweat more on other parts of their body afterward, he added.

Few people — including primary care physicians — know that so many treatment options for excessive sweating are available, Dr. Gorenstein said. The condition is “underdiagnosed and underreported,” he said, but thankfully, it can be managed.