What Is Hyperhidrosis and How Can It Be Treated?

Sweating is a normal and necessary function of the human body. It regulates temperature, protects you from overheating, and responds to physical exertion and stress. But for people living with hyperhidrosis, sweating goes far beyond what the body actually needs. It happens unpredictably, in excess of any physiological demand, and often at the most inconvenient moments. If you find yourself avoiding handshakes, changing clothes multiple times a day, or feeling anxious about visible sweat patches despite normal temperatures, you are not alone, and you are not without options.

Hyperhidrosis is a recognised medical condition that affects an estimated 1 to 3 percent of the population. It is frequently underdiagnosed because many people assume that excessive sweating is simply part of who they are, or feel embarrassed to discuss it with a medical professional. In reality, it is a physiological condition with a well-established mechanism and highly effective treatments available.

Understanding the Two Types of Hyperhidrosis

Hyperhidrosis falls into two distinct categories: primary focal hyperhidrosis and secondary generalised hyperhidrosis.

Primary focal hyperhidrosis is the more common of the two. It affects specific, localised areas of the body, most often the armpits, palms, soles of the feet, and sometimes the face or scalp. It is not caused by an underlying medical condition or medication. Instead, it appears to result from overactivity in the sympathetic nervous system, which overstimulates the eccrine sweat glands in these areas. Primary hyperhidrosis often begins in childhood or adolescence and tends to run in families.

Secondary generalised hyperhidrosis, by contrast, involves excessive sweating across a wider area of the body and is typically linked to an underlying cause such as a hormonal condition, infection, neurological disorder, or a side effect of medication. This type tends to present in adulthood and often occurs during sleep, which is less characteristic of the primary form.

The treatments described in this article are aimed at primary focal hyperhidrosis, which is the type most commonly presented in an aesthetic and medical clinic setting.

Which Areas Are Affected?

The three most commonly treated sites are the axillae (armpits), the palms of the hands, and the soles of the feet. Each presents its own particular set of challenges and impacts on daily life.

Axillary hyperhidrosis, or excessive sweating of the armpits, is perhaps the most visible and socially disruptive form of the condition. People with axillary hyperhidrosis often describe soaking through clothing within minutes of getting dressed, needing to carry spare tops, avoiding light coloured or fitted clothes, and feeling self-conscious in social and professional environments. The constant dampness can also lead to skin irritation, maceration, and an increased risk of secondary bacterial or fungal infection in the affected area.

Palmar hyperhidrosis, or excessive sweating of the palms, is one of the most functionally disruptive presentations. The hands are central to almost every aspect of daily interaction, from typing at a keyboard and handling documents, to physical contact with other people. Those living with palmar hyperhidrosis often describe avoiding handshakes entirely, struggling with grip on everyday objects, and finding that the condition causes significant professional embarrassment. In more severe cases, the skin of the palms can become macerated, tender, or prone to peeling.

Plantar hyperhidrosis, or excessive sweating of the feet, is frequently experienced alongside palmar hyperhidrosis and is often the least discussed despite being highly impactful. Persistently damp feet create an environment that promotes odour, blistering, fungal infections, and skin breakdown. It can affect the choice of footwear, the ability to wear open shoes or go barefoot, and causes significant discomfort throughout the day.

How Does Botulinum Toxin Treat Hyperhidrosis?

The most effective clinic-based treatment for primary focal hyperhidrosis is botulinum toxin injected directly into the affected area. While botulinum toxin is widely associated with the treatment of fine lines and wrinkles, its mechanism of action makes it equally well suited to the management of excessive sweating.

Sweat production is controlled by the sympathetic nervous system via a chemical messenger called acetylcholine. When acetylcholine is released at the nerve endings that supply the eccrine sweat glands, it triggers those glands to produce sweat. Botulinum toxin works by blocking the release of acetylcholine at these junctions, effectively interrupting the signal from the nerve to the sweat gland. The gland remains structurally intact, but the instruction to produce sweat is not received. The result is a significant and reliable reduction in sweating in the treated area.

This is not a permanent change to the body. Over time, the nerve endings regenerate and the effect gradually wears off, which is why the treatment requires periodic maintenance. For most patients, results last between four and nine months in the axillae, with palmar and plantar treatments sometimes requiring slightly higher doses and potentially offering a shorter duration of effect.

What to Expect at Karwal Aesthetics

At Karwal Aesthetics, hyperhidrosis treatment is carried out by Dr Arun Karwal, our clinical director, at our Mayfair clinic. A thorough consultation precedes any treatment, both to confirm that your sweating is consistent with primary focal hyperhidrosis and to assess the treatment area, discuss your medical history, and ensure the approach is appropriate for you.

The treatment itself involves a series of small, superficial injections placed across the affected area using a fine needle. For axillary treatment, a starch-iodine test can be used beforehand to map the precise area of sweating, ensuring that the injections are placed accurately and efficiently. The number of injection points varies depending on the area being treated and its size.

The procedure takes around thirty to forty-five minutes in total and does not require any significant downtime. Most patients notice a meaningful reduction in sweating within one to two weeks of treatment, with the full effect establishing over the following fortnight.

Side Effects and Safety

Botulinum toxin treatment for hyperhidrosis has a well-established safety record when administered by a trained medical professional. Side effects are generally mild and temporary. In the axillae, these may include localised bruising, redness, or tenderness at injection sites, all of which typically resolve within a few days. In the palms, compensatory sweating in untreated areas is occasionally reported, and there is a small risk of temporary and mild hand weakness if the toxin diffuses into adjacent musculature, though this is uncommon with careful technique. Plantar treatment can occasionally cause temporary foot weakness or altered sensation, which resolves as the product wears off.

Because the precision of placement directly affects both the efficacy and the safety profile of the treatment, the experience and clinical training of the person administering it matters considerably. At Karwal Aesthetics, all injectable treatments are carried out by Dr Karwal, ensuring that the assessment, dosing, and technique are managed to the highest clinical standard.

Is Hyperhidrosis Treatment Right for You?

If excessive sweating is affecting your confidence, your professional life, your relationships, or simply your comfort on a daily basis, it is worth exploring treatment. Hyperhidrosis is a legitimate medical condition, not a hygiene issue or a personal failing, and effective management is available.

Treatment is suitable for most healthy adults with primary focal hyperhidrosis who have not responded adequately to topical treatments such as prescription-strength antiperspirants. It is not suitable during pregnancy or breastfeeding, or for those with certain neuromuscular conditions. A full consultation with Dr Karwal will determine whether it is the right approach for you.

To book your consultation at our Mayfair clinic, visit our booking page. We accept online bookings only.