Excessive Sweating: Causes and How to Manage It

Excessive sweating is often hyperhidrosis — a medical condition in which the body produces more sweat than it needs to cool itself. The American Academy of Dermatology (AAD) splits it in two: primary (focal) hyperhidrosis, concentrated in one or two areas, and secondary hyperhidrosis, which usually causes heavy sweating over most of the body.

How common it is

A national survey published in Archives of Dermatological Research in 2016 found hyperhidrosis in 4.8% of the U.S. population — about 15.3 million people. The same survey found the condition is largely unspoken: only 51% had ever discussed their sweating with a healthcare professional, and of those, just 53% received a diagnosis. Mean age at which symptoms first appear was just under 20 years.

Where people sweat, by share of respondents in that survey: underarms 65%, head and face 42%, hands 40%, feet 38%.

Primary vs. secondary hyperhidrosis

• Primary (focal) hyperhidrosis — the most common type. It usually develops in one or two areas: underarms, palms, soles, scalp and face. For most people signs begin in childhood or adolescence, and sweating stops during sleep: most people wake up dry. Sweating tends to lessen with age, though it can be lifelong.
• Secondary hyperhidrosis — less common, and it usually causes heavy sweating over most of the body, which can happen even when it’s cool and you’re sitting at rest. It develops when you take certain medication or have another medical condition, and it can continue while you sleep.

Signs that help tell the types apart

Sign	Primary focal	Secondary
Onset	Childhood or adolescence	Can start at any age
Affected area	One or two areas (underarms, palms, soles, scalp, face)	Most of the body
Occurs during sleep	No — most people wake up dry	Yes, it can
Cause	Not fully known	Medical condition or medication

Common triggers reported with primary hyperhidrosis include hot weather, high humidity, feeling anxious or nervous, physical activity, and caffeine. Ordinary sweating has its own triggers that have nothing to do with hyperhidrosis — heat, exercise, anxiety, fever, and menopause all make the body sweat more. Persistently wet skin brings its own problems: body odor, macerated skin that turns wrinkly and soft and may peel, chafing, and frequent skin infections.

Treatments for excessive sweating

The AAD’s ladder, roughly in the order it’s usually tried:

• Antiperspirants. Treatment often begins here. Non-prescription products work for mild cases; most patients need prescription strength.
• Medicated cloth or gel for the underarms — glycopyrronium cloth or sofpironium gel, both cleared for patients aged 9 and up.
• Botulinum toxin injections for underarms, hands, feet, or face; results last roughly 3 to 10 months depending on the site.
• Iontophoresis for hands and feet: an electric-current device, 5 to 10 initial sessions and then maintenance.
• Microwave thermolysis and the in-office sweat-control patch, whose effect lasts about 2 to 4 months.
• Oral medication — glycopyrrolate or oxybutynin, which act body-wide, or propranolol for event-related sweating.
• Surgery, including sweat gland removal and sympathectomy, for severe cases.

When the sweating is secondary, treatment also means identifying and treating the underlying condition or adjusting the medication responsible, always under medical guidance.

What to do about excessive sweating

1. Observe the pattern: which areas, whether it continues during sleep, and when it started.
2. Note the triggers, such as heat, humidity, anxiety, activity, or caffeine.
3. Watch the skin for maceration, chafing, or signs of infection.
4. See a dermatologist to establish which type it is and which of the treatments above fits.

When excessive sweating needs medical attention

Sweating that covers most of the body, starts in adulthood, or continues while you sleep points toward the secondary form — that is, toward a medical condition or a medication as the cause — and should be evaluated. Note how underused care is here: about half of people with hyperhidrosis have never raised it with a clinician, and it is a treatable condition.

This content is informational and does not replace a medical consultation, diagnosis, or treatment. See also night sweats: causes.