What Is Hyperhidrosis?
Hyperhidrosis is sweating that significantly exceeds what is needed for thermoregulation — it occurs unpredictably, often without heat or exercise, and is severe enough to impair daily activities and social interactions. Surveys show it has a greater impact on quality of life than many recognised skin conditions. About 4.8% of Americans (roughly 15 million people) are affected, yet fewer than half seek medical help — many wrongly assume nothing can be done.
Primary vs Secondary Hyperhidrosis
Primary (Focal) Hyperhidrosis
The most common type — idiopathic (no underlying cause), focal (limited to specific body parts), and typically bilateral and symmetric. Most commonly affects the palms, soles, armpits (axillae), face, or groin. It usually begins in childhood or adolescence, has a positive family history in ~65% of cases, and is notably absent during sleep. The underlying mechanism involves overactivation of eccrine sweat glands by the sympathetic nervous system, though the trigger for this is unknown.
Secondary (Generalised) Hyperhidrosis
Sweating that is diffuse (all over the body), occurs during sleep (night sweats), and is new-onset in adulthood suggests a systemic cause:
- Hyperthyroidism and other endocrine disorders (acromegaly, phaeochromocytoma, carcinoid)
- Menopause and hormonal fluctuations
- Infections (TB, HIV, endocarditis)
- Lymphoma and other malignancies
- Medications (antidepressants, opioids, some diabetes medications)
- Obesity, diabetes, and metabolic syndrome
Treatments for Primary Hyperhidrosis
Antiperspirants
The first step — prescription-strength aluminium chloride hexahydrate (20–25%) applied to dry skin at night is significantly more effective than over-the-counter antiperspirants. Applied 2–3 nights per week, it can reduce sweating by 40–70% in axillary hyperhidrosis.
Iontophoresis
A device passes a mild electrical current through water to the skin surface of hands or feet — disrupting eccrine gland function. Sessions last 20–30 minutes, 3–4 times per week initially, then weekly for maintenance. Very effective for palmar and plantar hyperhidrosis; cumbersome but low risk. Devices can be purchased for home use.
Botulinum Toxin (Botox) Injections
Injections of botulinum toxin A into the axillae, palms, or soles block acetylcholine release at the sweat gland nerve junction. Axillary hyperhidrosis responds particularly well — 82–87% of patients achieve >50% sweat reduction lasting 4–7 months. Palmar injections require local anaesthesia (nerve block) because of the density of nerve endings. Most effective, evidence-based treatment for moderate-to-severe primary hyperhidrosis.
Oral Medications
Anticholinergic agents (glycopyrrolate, oxybutynin) block the neurotransmitter (acetylcholine) that stimulates sweat glands throughout the body. Effective but cause dose-dependent side effects: dry mouth, blurred vision, constipation, and urinary retention. Glycopyrronium cloth wipes (Qbrexza) offer a topical anticholinergic with less systemic absorption — approved specifically for axillary hyperhidrosis.
miraDry and ETS Surgery
miraDry uses microwave energy to permanently ablate sweat glands in the axillae — a single treatment producing sustained reduction. Endoscopic thoracic sympathectomy (ETS) surgically disrupts the sympathetic chain to permanently reduce palmar/facial sweating, but compensatory sweating elsewhere is a common and sometimes severe side effect.