DEAR DOCTOR K:
I’m a woman in her 70s. My problem is that I sweat heavily, day and night. Of course, it’s worse in the summer. I’m way past menopause. What can I do?
Doctors call excessive sweating “hyperhidrosis.” It is not a rare problem; I’ve treated many patients for it. In every case, they waited a long time before talking about the problem. That’s because they thought it was such a trivial issue that they didn’t want to waste the doctor’s time.
Hyperhidrosis is not trivial. Excessive sweating can reduce 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 we exercise, or in hot weather, we start to heat up. Our body needs to lose that heat. When we sweat, the evaporation of sweat from our skin causes the loss of body heat.
How do we sweat? Sweat is made by little glands under the skin — little sacs that fill with fluid. They are called eccrine glands and are activated by signals from the brain. The signals release a chemical called acetylcholine from nerve endings near the gland. That activates the glands to squeeze the fluid up through a little pore or channel, where it then spills out on the surface of the skin.
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. The more salt the antiperspirant contains, the longer it will work. If over-the-counter antiperspirants aren’t strong enough, try a prescription-strength preparation.
- 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. As many as 10 initial sessions usually are required to stop sweating. These are followed by weekly maintenance sessions. This procedure can also be used on underarms.
- Botulinum toxin A (Botox) injections are FDA-approved for underarm hyperhidrosis and are also effective for hands and feet. Multiple injections are required. Botox blocks the release of acetylcholine in the nerve endings. This prevents the nerve cells from communicating with sweat glands.
- Some doctors prescribe oral medications that reduce the activity of acetylcholine. But acetylcholine has many functions in the body, so these drugs can have many side effects.
- If your problem is severe and other options don’t work, you may need to consider surgery to remove the affected sweat glands. But usually the other options work, making surgery unnecessary.
(This column is an update of one that ran originally in July 2013.)