Excessive Sweating and Hyperhidrosis: Causes and Treatment Options

Sweating is physiologically normal and necessary. It’s the body’s primary mechanism for thermoregulation, and the amount of sweat produced under physical or thermal stress is highly variable between individuals without any of it constituting a medical concern. Hyperhidrosis is different: it’s sweating that exceeds what thermoregulation requires, is often unpredictable and disproportionate to the trigger, and causes significant functional or social disruption to the person experiencing it.

The condition is more common than most patients realise, and it’s more treatable than most patients have been led to believe. This article sets out what’s causing it, how we distinguish between types, what can be addressed in clinic, and what requires a medical conversation with your GP before any aesthetic treatment begins.

What Hyperhidrosis Is

Sweat is produced by eccrine glands, which are distributed across most of the body surface and respond to thermal and emotional stimuli via cholinergic nerve signals. In hyperhidrosis, those glands produce sweat in excess of what’s physiologically needed, even in the absence of heat or exertion, and often triggered by mild emotional stimuli such as mild anxiety or social situations that wouldn’t cause a noticeable sweat response in most people.

The clinical threshold is sweat production that interferes significantly with daily activities, including work, relationships, clothing choices, physical contact, and self-confidence. Patients often describe having managed it privately for years before seeking any help, assuming it’s just who they are rather than a condition with effective management options.

Primary vs Secondary Hyperhidrosis

This distinction is clinically important and the starting point for any assessment.

Primary hyperhidrosis has no identifiable underlying medical cause. It’s focal, meaning it affects specific areas rather than the whole body, typically bilateral and symmetrical, and usually begins in childhood or adolescence. A family history is common. The sweating tends to cease during sleep, which is a useful differentiating feature. Primary hyperhidrosis is what most patients presenting to an aesthetic or medical clinic are describing.

Secondary hyperhidrosis is caused by an underlying medical condition or medication. It’s more likely to be generalised rather than focal, may be associated with night sweats, and typically has an adult onset without a childhood history. Causes include thyroid dysfunction, diabetes, menopause, certain infections, malignancy, and a range of medications. Secondary hyperhidrosis must be investigated and the underlying cause managed before any symptomatic treatment is appropriate.

The features that should prompt a GP assessment before any clinic treatment:

• New onset sweating in an adult with no childhood history
• Generalised rather than localised sweating
• Night sweats alongside daytime hyperhidrosis
• Associated weight loss, fever, fatigue, or other systemic symptoms
• Sweating that doesn’t stop during sleep

If any of these apply, the right first step is your GP rather than a clinic. We’ll ask these questions at consultation and refer rather than treat if the picture suggests secondary hyperhidrosis.

Where Primary Hyperhidrosis Occurs

The most common sites for primary focal hyperhidrosis are:

Axillary (underarms). The most frequent presentation, and the one with the most clinically straightforward treatment pathway. Axillary hyperhidrosis significantly affects clothing choices, social confidence and professional interactions. Most patients have tried clinical-strength antiperspirants before considering further treatment.

Palmoplantar (palms and soles). Significant functional impact, affecting handshakes, keyboard use, driving, and the confidence to touch or be touched. More complex to manage than axillary hyperhidrosis.

Craniofacial (face and scalp). Sweating of the forehead and scalp that can be visible and distressing, particularly in professional or social contexts.

Truncal (chest and back). Less commonly the primary complaint, but frequently accompanies axillary hyperhidrosis.

Most patients have sweating predominantly in one or two areas, and the treatment approach is tailored accordingly.

What to Try Before Clinic Treatment

NICE guidance recommends a stepwise approach to hyperhidrosis management, and clinical-strength antiperspirant is the appropriate first step for most patients with mild to moderate primary axillary hyperhidrosis.

Clinical-strength antiperspirants. Products containing aluminium chloride at concentrations of 15 to 20 per cent (available as Driclor, Anhydrol Forte, and equivalents) work by forming a gel plug within the eccrine duct, physically blocking sweat from reaching the skin surface. They’re applied to completely dry skin, usually overnight, and washed off in the morning. Skin irritation is the most common side effect, manageable by reducing application frequency. For mild to moderate axillary hyperhidrosis, consistent use of a clinical-strength formulation significantly reduces sweating in most patients.

If you’ve tried this approach properly, meaning the correct formulation applied consistently, and it hasn’t provided adequate control, the next steps are worth discussing in consultation.

Iontophoresis. For palmoplantar hyperhidrosis specifically, iontophoresis uses mild electrical current passed through water in which the hands or feet are submerged, temporarily disrupting eccrine duct function. It can be done at home with a purpose-built device. It requires regular sessions to maintain effect and is more suited to hands and feet than to axillary or craniofacial hyperhidrosis.

Oral medication. Anticholinergic medications, including glycopyrronium and oxybutynin, reduce sweating systemically by blocking cholinergic nerve signals to eccrine glands. They require a GP or specialist prescription and have systemic side effects including dry mouth, blurred vision and urinary retention. They’re an option for patients with widespread hyperhidrosis or when localised treatments haven’t been adequate.

Injectable Treatment for Axillary Hyperhidrosis at LRC

For primary axillary hyperhidrosis that has not responded adequately to clinical-strength antiperspirant, injectable treatment is the most clinically effective and well-evidenced option available. NICE recommends it as an option for primary axillary hyperhidrosis when topical treatment has not provided adequate control.

The treatment works by temporarily interrupting the nerve signals that stimulate the eccrine sweat glands in the treated area. Small, precisely placed injections are made across the axilla at a grid of points, targeting the gland-dense zones where sweating is most active. The nerve signal is blocked, the glands stop producing sweat in that area, and the result is a meaningful, sometimes dramatic, reduction in axillary sweating.

Before treatment, we use a diagnostic technique called the starch-iodine test to map the active sweating zones. Iodine solution is applied to the axilla, then starch powder is dusted over it. Where eccrine glands are actively producing sweat, the iodine and starch react to form a dark brown colour, making the high-density zones visible and allowing the injections to be precisely targeted to where the glands are most active.

What to expect. The injections are made with a fine needle and are generally well tolerated. Some patients find the axilla area mildly uncomfortable at a few points; most describe it as very manageable. The session takes around 30 to 45 minutes for both axillae.

Results. Most patients notice a significant reduction in sweating within one to two weeks of treatment. The effect is not permanent: it lasts typically 6 to 12 months, with many patients finding the duration extends with repeated treatment. At the first signs of sweating returning, patients return for a top-up. Over time, many find the interval between treatments increases.

Pricing is discussed at consultation. As a prescription treatment, we don’t publish prices ahead of the prescribing consultation, where we confirm suitability and the appropriate dose.

Following an in-person consultation with our prescribing clinician, in line with current GMC, NMC, GPhC and GDC guidance.

What Injectable Treatment at LRC Cannot Do

Injectable treatment is primarily indicated and most effective for axillary hyperhidrosis. It can be used for craniofacial hyperhidrosis in selected patients, and occasionally for other sites, but the evidence base and practical experience is strongest for the axilla. For palmoplantar hyperhidrosis, the treatment is used but is more complex and may require more injections and a different clinical approach. We discuss this at consultation.

It doesn’t treat the underlying condition. Primary hyperhidrosis is a chronic condition with a neurological basis. Injectable treatment manages the symptom at the treated site while it’s effective. It doesn’t eliminate the tendency to hyperhidrosis across the body or prevent sweating at untreated sites.

When to Consider Surgical Options

For severe, generalised, or treatment-resistant hyperhidrosis, surgical options exist. Endoscopic thoracic sympathectomy (ETS) severs the sympathetic nerves supplying the sweat glands of the hands and face. It produces dramatic, permanent reduction in palmar and craniofacial sweating but carries a significant risk of compensatory hyperhidrosis, whereby sweating increases elsewhere in the body, most commonly the trunk. It’s a last resort for severely affected patients and requires specialist surgical referral.

We don’t offer surgical management at LRC. Where patients are considering or asking about surgery, the appropriate route is referral to a specialist vascular or thoracic surgeon with experience in ETS.

Frequently Asked Questions

Is hyperhidrosis a medical condition or just heavy sweating?

Primary hyperhidrosis is a recognised medical condition characterised by eccrine gland overactivity disproportionate to thermoregulatory need. It has a neurological basis, a genetic component, and a meaningful impact on quality of life. Framing it as “just heavy sweating” undersells the disruption it causes. NICE has published specific guidance on its management, including the use of clinical treatments when first-line measures don’t provide adequate control.

How do I know if I have primary or secondary hyperhidrosis?

The main distinguishing features are site, pattern and associated symptoms. Primary hyperhidrosis is focal, bilateral, begins in childhood or adolescence, doesn’t occur during sleep, and has no identifiable medical cause. Secondary hyperhidrosis is more likely generalised, with adult onset, associated night sweats, and possible systemic symptoms. If your sweating began suddenly in adulthood, is generalised, or is accompanied by other symptoms, see your GP before seeking aesthetic treatment.

Is the injectable treatment available on the NHS?

NICE recommends the treatment for primary axillary hyperhidrosis when topical treatment has not provided adequate control. In practice, NHS access varies significantly by region and commissioning decisions. Many patients find the NHS pathway either unavailable or subject to long waits, and come to LRC for private treatment. We confirm pricing at consultation.

How long does the injectable treatment last?

Most patients find the result lasts between 6 and 12 months. Some find the effect is shorter initially and extends with repeated treatments as the glands respond to repeated interruption of nerve signalling. When sweating returns, patients return for a top-up. We typically review at 6 months and treat when the patient notices the effect reducing.

Does the treatment hurt?

The axillary area is generally well tolerated. Injections are made with a fine needle and the treatment is comparable to other injectable treatments in terms of comfort. Some points in the axilla feel slightly more than others. Most patients find it very manageable and far preferable to the ongoing impact of the condition. We use the starch-iodine test to target injections precisely, which means we treat only the active zones rather than covering the whole area uniformly.

Can it treat sweating on my palms and feet?

Yes, though this is more complex than axillary treatment and may require a larger number of injections and a different approach to managing the higher nerve density in these areas. The evidence base for palmar and plantar hyperhidrosis is well-established, and the treatment is effective in most patients. For palmoplantar hyperhidrosis specifically, we’ll discuss iontophoresis as a first-line home option before injectable treatment at consultation.

Will treating the axillae cause sweating to increase elsewhere?

This is a reasonable concern. The injectable treatment interrupts nerve signals to the treated eccrine glands; it doesn’t affect sweat production elsewhere in the body. Compensatory sweating, where reduced sweating at one site is offset by increased sweating at another, is a recognised complication of surgical sympathectomy but is not a feature of injectable treatment. Your overall sweating physiology remains unchanged; only the treated glands are temporarily affected.

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