Hyperhidrosis: excessive sweating, causes and treatment

Hyperhidrosis is a condition in which you sweat excessively and unpredictably, even when it is cool or you are sitting still. It is not contagious, and most people who have it are otherwise healthy. There are two types, and knowing which one you have changes the treatment.

Primary (focal) hyperhidrosis: the heavy sweating is concentrated on the palms, the soles of the feet, the underarms or the head and face. No other disease causes it, it often runs in families, and it usually starts in childhood or the teen years.

Secondary hyperhidrosis: another condition or a medicine causes it. It can be all over the body (generalized) or in one area, and it sometimes starts suddenly in adulthood. In that case, treating the cause is what controls the sweating.

The main symptom is sweat, but what matters is how much it gets in the way of your day. The most common signs are:

• Sweaty hands that soak paper, your phone or the keyboard
• Underarm sweating that soaks or stains your clothes
• Sweaty feet that slip in your shoes or smell strongly
• Sweating on the face or head without heat or exercise
• Soft, irritated or infected skin from staying wet for long periods

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According to MedlinePlus, secondary hyperhidrosis can come from many conditions. Get checked soon if the sweating started suddenly all over your body or comes with fever or unexplained weight loss.

Sweats that wake you at night and soak your bedding are a different situation with different causes: see night sweats.

The causes the doctor looks for most often are:

• Overactive thyroid: hyperthyroidism speeds the body up and causes sweating, feeling hot, a racing heart and weight loss.
• Low blood sugar: low blood sugar causes cold sweats, shakiness and confusion, especially if you use insulin or other diabetes medicines.
• Diabetes: type 2 diabetes and swings in blood sugar can change how you sweat.
• Medicines: certain medicines and substances can cause sweating as a side effect; the doctor reviews what you take.
• Menopause: the hot flashes of menopause bring sudden sweating on the face, neck and chest.
• Infections: an infection, including tuberculosis, can cause sweating with fever.
• Anxiety: nerves increase sweating, especially on the hands and underarms.

Hyperhidrosis has no cure, but it does have treatment, and you almost always start with the simplest option. If it is secondary, treating the cause comes first.

Clinical-strength antiperspirant: antiperspirants with aluminum chloride are the first treatment for underarm sweating. You apply them at night to dry skin, every night until the sweating is under control and then once or twice a week. They can irritate the skin.

Glycopyrronium cloth: a prescription pre-moistened cloth you wipe on your underarms once a day. The FDA approved it for primary underarm hyperhidrosis in adults and children 9 and older. It can cause dry mouth, and blurred vision if it gets near your eyes, so you wash your hands after using it. It is not used if you have glaucoma or other conditions the doctor asks about.

Medicine by mouth: oral glycopyrrolate reduces sweating all over the body. It is not FDA-approved for hyperhidrosis (it is an off-label use), but it is used when the doctor judges it appropriate. It causes dry mouth and, because you sweat less, you need to be careful in the heat.

Iontophoresis: you place your hands or feet in water with a mild electric current for 20 to 30 minutes. It takes several sessions and then maintenance. We refer you to get started.

Botulinum toxin (often called Botox): injections block the nerves that switch on sweating in the underarms, hands, feet or face. Sweating drops within 7 to 10 days and the effect lasts for months. We refer you to a skin specialist who gives it in person.

Severe cases can be treated with surgery, such as sympathectomy, which carries risks like heavier sweating elsewhere on the body. The doctor explains whether it is worth considering.

With the island’s heat and humidity, everyone sweats, and it is easy to assume yours is normal. The difference is that with hyperhidrosis you sweat even in air conditioning or at rest, and the sweat gets in the way of work, school or your social life.

Skin that stays wet gets irritated and can develop heat rash or fungal infections. Wear cotton or quick-drying fabrics, change your socks during the day and dry well between your toes. If you use a medicine that reduces sweating, drink water, stay in the shade and avoid hard exercise at midday, because your body cools down less well.

Primary hyperhidrosis usually starts in childhood or the teen years. A child with sweaty hands may avoid shaking hands, writing on paper or going to school. We see patients of all ages: if you are under 21, your parent or legal guardian is on camera for the whole visit. The doctor evaluates the child and, if appropriate, prescribes a treatment suited to their age; the glycopyrronium cloth is approved from age 9.