Knowledge Base · Botulinum Toxin Treatments

Hyperhidrosis — Anatomy and Treatment Logic

Excessive sweating on the underarms, hands or feet can be treated. How botulinum toxin type A blocks the eccrine sweat glands, when treatment makes sense, and what a realistic expectation looks like.

A note on terminology: Many patients search for “Botox” — a brand name of one single product that has become a colloquial umbrella term. The active substance is botulinum toxin type A, contained in several licensed medicinal products. All of them are prescription-only and are injected exclusively by the physician after a medical examination. This page uses the substance name throughout — it refers to the same treatment commonly known as a Botox treatment.

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What you’ll find here: What hyperhidrosis is, four indications (underarms, hands, feet, intimate), the treatment concept with botulinum toxin type A — and in particular the anesthesiology core competence: nerve blocks for near-painless treatment of hands and feet. Jump straight to the four treatment options.

Excessive sweating — hyperhidrosis — affects around 2–3% of the population. In its primary focal form, it isn’t about heat, exertion or a symptom of illness — it’s an uncontrollable sweating tendency, often starting in adolescence, that complicates social situations, ruins clothing and weighs on self-esteem. Treatment with botulinum toxin type A has been approved in Germany since 2003, is well established and highly effective. For the underarms it’s a routine treatment. For hands and feet it becomes painful without nerve blocks — and this is exactly where Praxis Ackermann’s anesthesiology background comes fully into play.

Reading time · approx. 11 minutesAudience · Patients with excessive sweatingLast reviewed · May 17, 2026

Table of Contents

What hyperhidrosis is — and isn’t
Diagnostic criteria and the Minor test
Mechanism of action at the sweat glands
The four indications at a glance
The anesthesiology core competence — nerve blocks for hands and feet
Complications and compensatory sweating
Health insurance reimbursement for primary focal hyperhidrosis
What this treatment is not
Questions patients ask
The evidence base

Section 1 · Definition

What Hyperhidrosis Is — And Isn’t

Hyperhidrosis is pathologically increased sweating that goes beyond what’s physiologically necessary. It occurs independent of outside temperature, physical exertion or emotional arousal. Classification distinguishes two main forms, whose treatment approaches differ fundamentally:

Form	Characteristics	Treatment Approach
Primary focal hyperhidrosis	Idiopathic, often since adolescence, bilateral and symmetric, limited to underarms/hands/feet/face. Familial clustering in around 60% of cases.	Local therapy is the treatment of choice — botulinum toxin, aluminum chloride, iontophoresis, suction curettage.
Secondary hyperhidrosis	A consequence of other conditions — an overactive thyroid, diabetes, lymphoma, infections, medication side effects.	Treat the underlying condition. Local treatment is secondary and does not address the cause.

Diagnostic prerequisite. Before botulinum toxin treatment is considered, secondary hyperhidrosis should be ruled out. With generalized sweating (whole body), night sweats, sudden onset in adulthood, or accompanying symptoms (weight loss, fever), evaluation by a primary care physician or internist is indicated.

Section 2 · Diagnosis

Diagnostic Criteria and the Minor Test

The diagnosis of primary focal hyperhidrosis is based on history-taking and clinical findings. International consensus criteria call for focal, visible, excessive sweating lasting at least 6 months, with at least two of the following characteristics:

Bilateral and relatively symmetric
Impairs daily activities
Occurs at least once a week
Onset before age 25
Family history
No sweating episodes during sleep

Minor Test (Iodine-Starch Test)

The Minor test is the established method for visualizing the affected sweating areas. The skin is coated with iodine solution and, once dry, dusted with starch. Wherever sweat is released, the iodine reacts with the starch and turns deep blue. This allows the treatment area to be outlined and marked precisely.

The Minor test in practice. For underarm treatments, the Minor test is routinely performed before the first treatment. It helps distinguish the truly hyperhidrotic area from normal sweating — not every underarm that sweats is hyperhidrotic. For hands and feet the test is used less often, since the entire surface is treated; the patient history is more informative here than the visualization.

Gravimetry

If particularly pronounced hyperhidrosis is suspected, or where it’s relevant to a health-insurance reimbursement request, gravimetry can be performed — measuring sweat production in milligrams per minute on filter paper. Values above 100 mg per minute per underarm are internationally classed as typical for hyperhidrosis. This objective quantification is often needed for reports and reimbursement applications.

Section 3 · Mechanism of Action

Mechanism of Action at the Sweat Glands

The eccrine sweat glands are innervated by sympathetic nerve fibers — unusual, since sympathetic fibers elsewhere rely on noradrenaline as their transmitter. At the sweat glands, however, it is acetylcholine that triggers sweat secretion. This is exactly where botulinum toxin type A acts — by cleaving the SNARE protein SNAP-25, it prevents the presynaptic release of acetylcholine at the sweat gland–nerve junction.

What this means in practice

Direct effect on the target region — no systemic effect
Onset after 2–5 days — full effect after 1–2 weeks
Duration of effect 4–8 months — noticeably longer than for facial-expression treatments, 6 months on average
Often longer-lasting with repeated treatment — the duration of effect can extend from cycle to cycle
Reduction of 80–95% — complete dryness is not the goal, and wouldn’t be physiologically sensible either

Complete dryness is not the goal. Treatment reduces sweat production to a “normal” level — it does not eliminate it. Sweating is an important bodily function for thermoregulation. A well-dosed treatment preserves physiological sweating and only reduces the excessive component.

Section 4 · Indications

The Four Indications at a Glance

Excessive sweating occurs at typical anatomical locations — the so-called “hot spots” of eccrine gland density. Four indications are established at Praxis Ackermann:

Underarm Hyperhidrosis

Routine Indication

The most commonly treated location. Intradermal wheal technique, roughly 50 units per side distributed across 15–20 points. Treatment possible in about 30 minutes without anesthesia.

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Hand Hyperhidrosis

With Nerve Block

Palmar hyperhidrosis. 100 units per hand across 30–50 intradermal points. Without a nerve block, treatment is very painful — the practice’s anesthesiology expertise makes it well tolerated.

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Foot Hyperhidrosis

With Nerve Block

Plantar hyperhidrosis. 100 units per foot. Here too, nerve blocks (tibial, peroneal and saphenous nerves) are the key to a well-tolerated treatment.

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Intimate Hyperhidrosis

Special Indication

Inguinal, perianal or genital hyperhidrosis — less discussed, but highly distressing for those affected. Treatment in a discreet, medically supervised setting.

View details →

Which region gets treated when? Most patients present with one primary location (underarms most commonly, hands second). Some have more than one — in these cases, priority follows the level of distress and the treatable surface area. Several regions can also be treated in the same appointment, provided the total dose stays appropriate.

Section 5 · Anesthesiology Core Competence

Nerve Blocks for Hands and Feet

While underarm treatment is routine in aesthetic medicine, hands and feet present a key difference: 30–50 intradermal injections into the palms or soles are very painful without anesthesia — these regions are among the most pain-sensitive skin areas of the body. This is exactly where the practice’s anesthesiology background comes fully into play.

What nerve blocks make possible

A selective nerve block surrounds the sensory nerves supplying the palm or sole with a small amount of local anesthetic. The region becomes numb for 2–4 hours. The botulinum toxin treatment can then be carried out without pain, with the same precision as on the underarm. A routine anesthesiology technique, applied to an aesthetic-medicine indication:

Brachial plexus block (axillary or supraclavicular) for hand treatment
Posterior tibial nerve, deep peroneal nerve and saphenous nerve for foot treatment
Ultrasound-guided for maximum safety and precision
Very small amounts of local anesthetic — effective for 2–4 hours, fully reversible
Expertise from daily anesthesiology practice: the same techniques used every day for surgery

Hand treatment — the typical procedure

Step	Description
1. Consultation and marking	History-taking, clinical examination, marking of the treatment area, explanation of procedure and side effects
2. Nerve block	Ultrasound-guided brachial plexus block. Onset after 10–20 minutes
3. Treatment begins	Once the hand is completely numb, 30–50 intradermal wheals are distributed evenly across the palm — typical total dose 100 units per hand
4. Observation	Observation until sensation fully returns (2–4 hours). The patient must not drive herself

Foot treatment — the typical procedure

Step	Description
1. Consultation and marking	As with hand treatment — plus assessment of the foot skin for fungal infection, which must be treated before the procedure
2. Nerve block	Three nerve blocks per foot: posterior tibial nerve (medial to the ankle bone), deep peroneal nerve (top of the foot), saphenous nerve (medial ankle) — ultrasound-guided
3. Treatment begins	After 15–25 minutes of onset time: intradermal wheals across the sole, typically 100 units per foot
4. Mobilization	Observation until sensation returns. The patient should have someone accompanying her

A pain-free hand or foot hyperhidrosis treatment with nerve blocks is anesthesiology routine — applied to an aesthetic-medicine indication. This expertise sets us apart from purely dermatological practices, where patients often experience pain as the limiting factor.

— Dr. Thomas Ackermann · Anesthesiology Practice Logic

Why this makes the difference in treatment

Complete treatment instead of partial. Without anesthesia, many patients discontinue hand treatment early — the pain is too intense. The effect becomes suboptimal as a result. With a nerve block, the entire surface can be treated precisely.
Higher treatment adherence. Patients who find the first treatment well tolerated come back for follow-up after 6 months. Those who found the first traumatic often don’t.
Better dose distribution. During a painful treatment the hand pulls back and injections become imprecise. With anesthesia the hand stays relaxed and distribution is even.
Safety. Ultrasound-guided nerve blocks are part of daily anesthesiology practice. Complications such as accidental intravascular injection or nerve damage are extremely rare with correct technique.

Section 6 · Safety

Complications and Compensatory Sweating

Hyperhidrosis treatment with botulinum toxin is, overall, very safe. With correct intradermal technique, side effects are rare. The most relevant possible effects:

Observation	Frequency	Duration
Local pressure pain / injection pain	Common (especially hand/foot without a block), brief	During treatment + 1–2 days
Bruising at injection sites	Occasional	3–7 days
Compensatory sweating	Occasional (5–15% of patients)	4–8 months (over the duration of effect)
Temporary hand-muscle weakness	Rare — from injection too deep into the lumbrical muscles	4–8 weeks
Local irritation / temporary redness	Common, brief	1–2 days
Treatment failure (insufficient effect)	Rare	—
Needle phobia / vasovagal reaction	Occasional	After treatment

Compensatory Sweating

When a hyperhidrosis area stops sweating, the body can sweat more at other sites — typically the back, abdomen or thighs. This is usually mild and transient, though it can be bothersome for some patients. The incidence is around 5–15% and depends on the treated surface area and dose. This is addressed during the consultation.

Complications of Nerve Blocks (Hand/Foot)

Temporary numbness lasting longer than planned (rare, 2–6 hours beyond the expected duration)
Bruising in the block area (occasional, resolves within 3–7 days)
Accidental intravascular injection (very rare with ultrasound-guided technique)
Nerve damage from needle contact (very rare, ultrasound significantly reduces the risk)

Anesthesiology routine reduces risk. Ultrasound-guided nerve blocks are part of daily anesthesiology craft. Safety is significantly higher than with “blind” puncture. Standardized emergency protocols for rare complications (local anesthetic toxicity) are established and routinely maintained — a concrete strength of the anesthesiology-based practice logic.

Section 7 · Reimbursement

Health Insurance Reimbursement for Primary Focal Hyperhidrosis

With documented primary focal hyperhidrosis and demonstrated distress, reimbursement through German statutory health insurance (GKV) is possible — but not automatic. The exact requirements vary between insurers, but typically follow these criteria:

Reimbursement Requirements

Documented diagnosis of primary focal hyperhidrosis (ICD-10: R61.0 or L74.5)
Evidence of unsuccessful prior treatment — typically aluminum chloride antiperspirants (for at least 4–8 weeks) and/or iontophoresis
Quantification of sweat production via gravimetry (>100 mg/min/underarm) or detailed clinical documentation
Documented quality-of-life impairment (e.g. Dermatology Life Quality Index DLQI >10)
Application submitted before treatment, to the health insurer, with a physician’s report

Typical Process

Step	Description
1. Primary-care pre-diagnosis	Ruling out secondary causes, initial documentation
2. Antiperspirant trial	Aluminum chloride–based products over 4–8 weeks, documented success/failure
3. Possibly iontophoresis	Especially for hands/feet — 8–12 sessions, evaluation of success
4. Consultation at Praxis Ackermann	Clinical examination, gravimetry, consultation, application support
5. Application to the health insurer	With a physician’s report. Approval typically within 2–4 weeks
6. Treatment	After approval, or as a self-pay service with subsequent submission

Practical recommendation. Many patients choose to pay for treatment themselves, since the application process takes time and isn’t always successful. For those who do want to try a reimbursement application, Praxis Ackermann provides the necessary medical documentation — this is discussed at the initial consultation.

Section 8 · Indication Boundaries

What This Treatment Is Not

Five Precise Distinctions

It is not a treatment for secondary hyperhidrosis. When sweating is a symptom of another condition (an overactive thyroid, diabetes, infections, lymphoma), the underlying condition needs to be treated. Botulinum toxin relieves the symptom, not the cause.
It does not work for generalized sweating. Treatment addresses focal areas (underarms, hands, feet, face). For whole-body sweating, the treatment area would be too large and the dose too high — other approaches (systemic anticholinergics, tablet therapy) are indicated there.
It is not a permanent cure. The effect lasts 4–8 months, after which sweating gradually returns. Those seeking lasting benefit undergo regular treatment. Surgical procedures (suction curettage for the underarms, sympathetic nerve procedures) are possible permanent alternatives, with their own risks.
It is not indicated for mild sweating. For a normal sweating tendency and cosmetic concern without an underlying condition, botulinum toxin is not the treatment of choice. Antiperspirants, sport-specific clothing and a good hygiene routine are enough. Treatment is medically indicated from the point of clinically relevant hyperhidrosis.
It does not change the number of sweat glands. Botulinum toxin temporarily blocks sweat production — the eccrine glands remain anatomically intact. Once the effect wears off, the original sweat volume returns. A permanent reduction in glands is only achievable through surgical procedures (suction curettage).

Section 9 · Questions Patients Ask

What Patients Want to Know in More Depth

Does treatment on the hands hurt a lot?

Without anesthesia: yes, hand and foot treatment is very unpleasant without pain relief — palms and soles are the most sensitive skin areas of the body. With a nerve block, the region is completely numb for the treatment. You won’t feel the wheals, and during treatment will only feel your hand being used for support. The anesthesia lasts 2–4 hours — everything is completed within that time.

How long do I need to wait after a hand or foot treatment?

You should stay at the practice for 2–4 hours, until sensation has fully returned. You must not drive with a numb hand — please arrange for someone to accompany you, or a taxi, for the way home. The treatment effect itself begins after 2–5 days and is fully noticeable after 1–2 weeks.

When will I see whether the treatment worked?

Initial reduction in sweating after 2–5 days, a clear effect after 7–10 days, full effect after 2 weeks. A follow-up appointment after 14 days makes sense — if individual points still show residual activity, targeted touch-up injections can be given.

How often do I need follow-up treatment?

On average every 6 months — some patients return after just 4 months, others not until 8–10 months. The duration of effect is highly individual and often lengthens with repeated treatment — many patients need longer intervals after 2–3 years than at the start.

What is compensatory sweating?

In a small group of patients (5–15%), increased sweating can occur at other body sites once one area has been treated. Typical locations: back, abdomen, thighs. The effect is mild to moderate and fades along with the effect of the actual treatment. For a few patients this can be a reason not to repeat treatment — this is discussed transparently during the consultation.

Is treatment possible during pregnancy?

No. Botulinum toxin is not used during pregnancy or breastfeeding, since there isn’t sufficient safety data. If you’re trying to conceive, a treatment pause is recommended — the next treatment would be possible once breastfeeding has ended.

How safe are the nerve blocks?

Ultrasound-guided nerve blocks are part of daily anesthesiology practice and are very safe. Direct visualization of the nerve significantly reduces the risk of nerve damage. The local anesthetics used are given in very small amounts — a systemic effect is not expected. Standardized emergency protocols for rare complications are in place and practiced regularly.

Can I exercise normally after treatment?

You should avoid exercise that causes heavy sweating for 24 hours — sweat over fresh injection sites raises the risk of infection. Walking and light movement are fine. After 24 hours there are no restrictions — quite the opposite, most patients notice a clearly improved quality of life during physical activity, since the treated areas stay dry.

What happens if I stop treatment?

Over 4–8 months, sweat production returns to its baseline level. There is no “rebound effect” — sweating does not become worse than before. Anyone wanting to take a break from treatment can do so without issue, and resume when needed.

What alternatives are there?

Aluminum chloride–based antiperspirants (first line), iontophoresis (especially for hands/feet), systemic anticholinergics (in select cases), surgical procedures such as suction curettage (for the underarms) or thoracoscopic sympathectomy (very rare, with its own risks). The decision is made individually — for most patients with focal hyperhidrosis, botulinum toxin offers the best benefit-to-risk profile.

Section 10 · The Evidence Base

What the Treatment Is Based On, Scientifically

Consensus recommendations Sommer/Bergfeld/Sattler, 2007 — Hyperhidrosis section

Consensus recommendations on the use of botulinum toxin A in aesthetic medicine. JDDG Supplement 1, Volume 5. Describes axillary hyperhidrosis treatment in detail: the Minor test as the standard for defining the area, gravimetry for quantification, 1 cm² fields with 3–5 units per field, an average of 47 units per side (35–50 units). Confirms that BTX-A has been approved in Germany for axillary hyperhidrosis since 2003. Most of the practical recommendations on this page are based on this consensus.

DOI 10.1111/j.1610-0387.2007.06204.x · 22 consensus participants · 18/22 use the Minor test routinely

Lowe NJ et al., 2007 — Phase III study, axillary hyperhidrosis

Botulinum toxin type A in the treatment of primary axillary hyperhidrosis: a 52-week multicenter double-blind, randomized, placebo-controlled study of efficacy and safety. Journal of the American Academy of Dermatology 56(4):604–11. Established efficacy for FDA and EMA approval of the indication. At 4 weeks, 75% of patients treated with botulinum toxin (75 U or 50 U per underarm) reached a ≥2-point improvement on the Hyperhidrosis Disease Severity Scale, versus 25% with placebo (P<.001); median duration of effect was 197–205 days versus 96 days with placebo.

DOI 10.1016/j.jaad.2007.01.009 · Phase III RCT · basis of international approval

Naumann M, Lowe NJ, 2001 — First large phase III study, axillary hyperhidrosis

Botulinum toxin type A in treatment of bilateral primary axillary hyperhidrosis: randomised, parallel group, double blind, placebo controlled trial. BMJ 323(7313): 596–599. The first large randomized trial of BTX-A for axillary hyperhidrosis. At 4 weeks, 94% of the botulinum toxin group were responders (≥50% reduction in sweat production), versus 36% with placebo.

DOI 10.1136/bmj.323.7313.596 · landmark RCT · BMJ publication

Schnider P et al., 2001 — Palmar and axillary hyperhidrosis, long-term follow-up

Treatment of focal hyperhidrosis with botulinum toxin type A: long-term follow-up in 61 patients. British Journal of Dermatology 145(2): 289–293. Confirms efficacy for palmar hyperhidrosis specifically: median reduction in sweat production of 71% (axillary) and 42% (palmar) at 4 weeks. Documents transient hand-muscle weakness in 9 of 21 palmar-treated patients — part of the basis for this page’s emphasis on adequate pain control and precise technique.

DOI 10.1046/j.1365-2133.2001.04349.x · RCT, palmar hyperhidrosis · 61-patient long-term follow-up

Anesthesiology literature — brachial plexus block and foot blocks

Standard anesthesiology textbooks (Pinnock/Lin/Smith, Hadzic) describe ultrasound-guided nerve blocks for the brachial plexus, posterior tibial nerve, deep peroneal nerve and saphenous nerve as established, very safe routine procedures. Applying these techniques to the aesthetic-medicine indication of hyperhidrosis treatment combines the anesthesiology background with the dermatological indication.

Anesthesiology standard · applied in practice

Botulinum toxin type A treatment for hyperhidrosis has been clinically established for over two decades. Combining it with anesthesiology-based nerve blocks for hand and foot treatment is a central part of the treatment logic at Praxis Ackermann — it is what makes palmar and plantar hyperhidrosis therapy practical for patients in the first place.

Which treatment region would you like to discuss?

The four treatment pages cover the procedure, requirements and consultation information:

Underarms

An overview of all botulinum toxin treatments is available on the category page.

For patients from the Erlangen area: wrinkle treatment in the Erlangen area.

· Hands · Feet · Intimate

Author and Last Review

Dr. med. Thomas Ackermann

Specialist in Anesthesiology · Medical Director, Harmonie der Ästhetik

Hyperhidrosis treatment is one of the most rewarding indications in aesthetic medicine — especially for hands and feet. Patients experience an immediate gain in quality of life, often visible after just the first treatment. The anesthesiology background here isn’t just a marketing point — it’s the technical prerequisite for making palmar and plantar hyperhidrosis treatment practical at all. Ultrasound-guided nerve blocks are daily routine, applied to an indication where patients would otherwise have to choose between pain and going without treatment. This page was last reviewed on May 17, 2026.

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