Hyperhidrosis: What Causes Excessive Sweating & How to Treat It

What hyperhidrosis actually is

Sweat is your body's cooling system. It kicks on when you overheat, then shuts off. Hyperhidrosis means that system runs without a good reason — at rest, in air conditioning, through the night. The sweat itself is normal; the signal driving it is not.

It tends to concentrate in specific spots: palms, the soles of your feet, underarms, face, and scalp. When sweating stays in one or two of those zones, doctors call it focal hyperhidrosis. When it spreads across the body more broadly, that's the generalized form. Focal is more common, more studied, and more treatable.

The social weight of this condition often goes unacknowledged. People cancel handshakes, avoid open-toe shoes, change shirts mid-day, and quietly rearrange their lives around sweat. Depression and social anxiety run noticeably higher in people with hyperhidrosis than in the general population — something that deserves more attention than it usually gets.

Primary vs secondary

Primary hyperhidrosis has no underlying medical cause. It tends to start in childhood or adolescence, runs in families, and stops during sleep (an important diagnostic clue). The exact mechanism isn't fully understood, but it seems to involve overactive nerve signals to the sweat glands rather than any abnormality in the glands themselves.

Secondary hyperhidrosis is a symptom of something else. It can appear at any age, often affects the whole body rather than just one spot, and usually continues during sleep. Finding and treating the underlying cause is the starting point.

Conditions and medications that can drive secondary hyperhidrosis

An overactive thyroid (hyperthyroidism) is one of the more common culprits. Diabetes — particularly episodes of low blood sugar — can trigger generalized sweating as the body responds to a falling glucose level. Menopause is another well-recognized cause, tied to changing hormone levels and the hot flashes that come with them.

Several medications list sweating as a side effect, including certain antidepressants (SSRIs and SNRIs especially), some blood pressure drugs like beta blockers, and opioids. Infections — including tuberculosis and endocarditis — can produce drenching night sweats. Rare adrenal tumors called pheochromocytomas release bursts of adrenaline and can cause episodes of severe sweating paired with a pounding heart and sudden high blood pressure.

If hyperhidrosis came on recently and nothing else explains it, that pattern warrants a workup.

Treatments that actually work

Clinical-strength antiperspirants are usually the first step. Products containing aluminum chloride hexahydrate are more effective than standard over-the-counter options and are applied at night to completely dry skin. They work by temporarily blocking sweat ducts.

For underarms, prescription glycopyrronium tosylate cloths are a newer option — they're an anticholinergic applied topically, which reduces the nerve signal to sweat glands without the systemic effects of taking the same drug by mouth.

Iontophoresis uses low-level electrical current passed through water to suppress sweating in the hands and feet. It requires multiple sessions per week at first, then maintenance, but it's non-invasive and has a good track record for palmar and plantar sweating.

Botulinum toxin (Botox) injections are FDA-cleared for axillary hyperhidrosis and used off-label for hands, feet, and forehead. Results last around six to twelve months. The injections are uncomfortable in the hands and feet in particular, but the effect is reliable.

Microwave thermolysis, sold under the brand name miraDry, delivers targeted microwave energy to destroy sweat glands in the underarms. Because sweat glands don't regenerate, results tend to be long-lasting. It's specific to the underarms and involves some downtime.

Oral anticholinergics like glycopyrrolate and oxybutynin reduce sweating across the body by blocking the nerve signals that activate sweat glands. They work, but systemic side effects — dry mouth, blurred vision, constipation, urinary retention — limit how much most people can tolerate.

A dermatologist can help figure out which approach fits your pattern, severity, and preferences. Most people work through options roughly in the order listed above.

When to see a doctor

Sweating that gets in the way of normal life is reason enough to make an appointment, even if nothing else feels wrong. That's a low bar on purpose — hyperhidrosis is treatable, and suffering through it quietly is not the only option.

Seek prompt attention if the sweating started suddenly and without explanation, affects only one side of the body, or shows up alongside unexplained weight loss, persistent fever, or night sweats that soak through clothing. A combination of heavy sweating with a rapid or irregular heartbeat, heat intolerance, and unintended weight loss can point to thyroid disease.

Go to the emergency room if sweating appears together with chest pain, difficulty breathing, sudden weakness on one side, confusion, or fainting. That cluster of symptoms can indicate a heart attack, stroke, or another medical emergency where the sweating is not the main problem.

What Glow can and can't do here

Glow reads ingredient labels and flags safety concerns in the products you use. If you have hyperhidrosis and you're managing it with prescription wipes, clinical-strength antiperspirants, or anything else you apply to your skin, Glow can tell you what's in those products and whether any ingredients have concerns worth knowing about. It can't diagnose hyperhidrosis, assess severity, or replace a conversation with a dermatologist or physician.