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Hyperhidrosis

SNOMED: 312230002888 words•Updated 03/03/2026

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Exam Tips

In OSCEs, distinguish primary focal from secondary generalized disease by distribution, age of onset, sleep pattern, and systemic red flags.
Use HDSS explicitly: 1-2 mild/moderate, 3-4 moderate/severe; this supports escalation decisions and referral justification.
Primary focal diagnostic pattern: focal visible sweating, at least 6 months, no clear cause, plus at least two characteristic criteria.
Night sweats with weight loss/fever should trigger urgent work-up for infection or malignancy rather than symptomatic treatment alone.
Always mention antimuscarinic contraindications and counseling points (glaucoma, urinary retention, cognitive/visual adverse effects).

Definition

Hyperhidrosis is excessive sweating beyond what is required for normal thermoregulation, causing functional or psychosocial impairment. It is classified as focal or generalized, and as primary (idiopathic, usually focal and symmetric) or secondary (due to an underlying medical condition, medication, or substance use/withdrawal). In UK clinical practice, primary focal disease most often affects axillae, palms, soles, or craniofacial sites and commonly starts in childhood or adolescence.

Pathophysiology

Primary focal hyperhidrosis is thought to reflect overactivity of sympathetic cholinergic stimulation of eccrine sweat glands rather than gland overgrowth, with a recognized familial tendency (about 30-50% report affected relatives). Emotional and thermal triggers can amplify sweating via central autonomic pathways, creating a feedback loop of anxiety and symptom worsening. Secondary hyperhidrosis results from systemic drivers (for example infection, endocrine excess, malignancy, neurological disease, drugs, or alcohol/drug withdrawal) that increase sweat output globally or regionally. For revision of mechanisms, see a standard physiology figure of sympathetic innervation of eccrine glands and a dermatome-based sweating distribution figure.

Risk Factors

Family history of primary focal hyperhidrosis
Adolescent age of onset (peak around 15-18 years)
Anxiety/stress and strong emotional arousal
Heat/exercise exposure
Smoking, alcohol, caffeine, spicy/citrus/hot foods, chocolate, sweets
Obesity
Medications associated with sweating (for example SSRIs/SNRIs, tricyclics, mirtazapine, trazodone, cholinesterase inhibitors, pilocarpine, opioids)
Alcohol or illicit drug misuse/withdrawal

Clinical Features

Symptoms

Visible excessive sweating at focal sites (axillae, palms, soles, craniofacial) or generalized over body surface
Episodes at least weekly in primary focal disease
Marked interference with daily tasks (writing, grip, device use, driving, instrument playing)
Social embarrassment, relationship strain, reduced school/work performance
Possible trigger-linked worsening with stress, heat, exercise, or dietary triggers
Red-flag associated symptoms suggesting secondary causes: fever, weight loss, anorexia, palpitations, night sweats

Signs

Bilateral, relatively symmetrical focal sweating in primary disease
Moist palms/soles or sweat staining in axillae; sometimes dripping palmar/plantar sweat
Localized sweating absent during sleep in primary focal hyperhidrosis
Complication signs: maceration, intertrigo, fungal infection, pitted keratolysis, bromhidrosis
Signs of secondary pathology on examination (for example thyrotoxicosis, infection, heart failure, neuropathy)

Investigations

Clinical diagnostic criteria for primary focal hyperhidrosis:Focal visible excessive sweating for at least 6 months with no clear cause, plus at least two of: bilateral/symmetric, impairs activities, at least weekly episodes, onset before 25 years, family history, absent during sleep.

Hyperhidrosis Disease Severity Scale (HDSS):Score 1-2 indicates mild-moderate disease; 3-4 indicates moderate-severe disease and usually justifies escalation.

Full blood count, ESR/CRP:Usually normal in primary disease; raised inflammatory markers or cytopenias may suggest infection, inflammation, or malignancy.

Urea/electrolytes, liver function tests, HbA1c, thyroid function tests:Usually normal in primary disease; abnormalities suggest endocrine/metabolic or systemic secondary causes.

Targeted tests: HIV/TB testing, malaria film, chest X-ray:Performed when history/exam indicates infection, travel risk, respiratory symptoms, or constitutional symptoms.

24-hour urine catecholamines/metanephrines and 5-HIAA:Used when features suggest phaeochromocytoma or carcinoid syndrome.

Management

Lifestyle Modifications

Explain condition type (primary vs secondary), trigger minimization, and realistic expectations (relapse common).
Use breathable clothing/footwear, absorbent insoles/socks, and regular skin care to reduce maceration/infection risk.
Address psychosocial impact and anxiety amplification; consider concurrent mental health support where needed.
Treat complications promptly (for example intertrigo, tinea pedis, pitted keratolysis, bromhidrosis).
Review and rationalize sweat-provoking medicines where clinically safe.

Pharmacological Treatment

Topical antiperspirant (first-line for focal disease)

Aluminium chloride hexahydrate 20% solution/roll-on: apply at night to completely dry skin for several nights until control, then maintenance 1-2 times weekly

Common local irritation/stinging; avoid application immediately after shaving or on broken/inflamed skin. Wash off in the morning; reduce frequency if irritant dermatitis occurs.

Topical anticholinergic (selected axillary cases, specialist/availability dependent)

Glycopyrronium bromide topical cloth 2.4%: one application daily to each axilla

Anticholinergic adverse effects possible (dry mouth, blurred vision, urinary symptoms). Avoid eye contact due to risk of mydriasis/precipitating angle-closure glaucoma symptoms.

Oral antimuscarinics (off-label in many UK settings; specialist-led if refractory)

Oxybutynin immediate-release: start 2.5 mg once daily, then titrate (for example to 2.5-5 mg two to three times daily) according to benefit/tolerability
Propantheline bromide: typically 15 mg three times daily before meals and 30 mg at bedtime

Use lowest effective dose. Contraindications/cautions include narrow-angle glaucoma, urinary retention, gastrointestinal obstruction/ileus, severe ulcerative colitis/toxic megacolon, and myasthenia gravis. Counsel on dry mouth, constipation, blurred vision, cognitive effects, tachycardia, and heat intolerance (reduced sweating may increase overheating risk).

Neurotoxin therapy

Botulinum toxin type A intradermal injections: commonly 50 units per axilla (specialist administration; dosing patterns vary by product/site)

Effective for axillary and some palmar/plantar disease. Adverse effects include injection pain, transient weakness (especially hands), and compensatory sweating; repeat treatments are usually required.

Surgical / Interventional

Iontophoresis for palmar/plantar hyperhidrosis when topical therapy is insufficient.
Local axillary procedures (curettage/liposuction or microwave thermolysis where available) for persistent focal axillary symptoms.
Endoscopic thoracic sympathectomy (usually for severe refractory palmar disease): discuss irreversible nature, compensatory hyperhidrosis risk, pneumothorax, Horner syndrome, and neuropathic pain before referral.

Complications

Quality-of-life impairment (functional, social, educational, occupational)
Anxiety and depressive symptoms
Bromhidrosis
Skin maceration and intertrigo
Secondary bacterial infection
Fungal infections (body/groin/feet)
Pitted keratolysis

Prognosis

Primary axillary and craniofacial hyperhidrosis may lessen with age and is less common in older adults, whereas palmar disease often worsens around puberty and may persist long term. Recurrence after treatment is common, so many patients need stepwise, repeated, or combined therapies. Prognosis is strongly influenced by symptom burden, comorbidity, and response to first-line topical measures.