What is excessive sweating, and why does it happen?
Sweating is a natural mechanism that regulates body temperature. In hyperhidrosis, the sweat glands overwork even in situations that do not involve heat or exertion. As a result, clothes can get wet, shaking hands or using paper or a keyboard can become difficult, and the person may avoid social situations.
Excessive sweating is divided into two main groups. This distinction is the most important step for the treatment plan.
- Primary focal hyperhidrosis: The most common type. It usually starts in childhood or adolescence and affects specific areas such as the armpits, palms, soles of the feet or face on both sides, symmetrically. A similar history in the family is common, and sweating usually does not occur during sleep. Its cause is not fully known; there is no underlying disease.
- Secondary hyperhidrosis: This occurs as a result of another condition. An overactive thyroid gland, diabetes, some infections, menopause, some medicines and, more rarely, other diseases can be the cause. It usually affects the whole body, is sometimes one-sided, may start at an older age and may be accompanied by night sweats.
In secondary hyperhidrosis, treatment targets the underlying cause of the sweating. This is why sweating that is widespread over the whole body, wakes you from sleep at night, has started recently in adulthood or is one-sided must be investigated by a physician before any aesthetic procedure.
With excessive sweating, the first question is whether it is primary or caused by something else. If sweating is widespread, wakes you at night or has newly started in adulthood, that cause needs to be investigated first.
Dr. Hamza GemiciMedical Director, DoktorClub · Aesthetic Medicine Physician
What is the aim of treatment, and in which areas is it done?
- Underarm sweating
- Sweating of the palms
- Sweating of the soles of the feet
- Sweating of the face and scalp (in selected people; requires more careful planning)
Treatment usually progresses in steps: simple methods with few side effects are tried first, and if they are not enough, the next step follows. Which step is suitable for you is decided together with the physician according to the location and severity of the sweating and how much it affects your life.
Treatment options, step by step
- Everyday measures: Cotton and breathable clothing, changing socks often, alternating shoes, and recognising triggers that increase sweating.
- Antiperspirant products: Products containing aluminium salts temporarily block the sweat ducts. Applying them in the evening to completely dry skin is usually recommended. A deodorant only reduces odour; it does not reduce sweating. Itching and irritation of the skin are the most common side effects. Stronger products are used on a physician's recommendation.
- Iontophoresis: The hands or feet are placed in a container of tap water, and a weak electrical current is passed through the water. It is used especially for sweating of the palms and soles of the feet. Frequent sessions are needed at first, followed by regular maintenance sessions. It may not be suitable in pregnancy or if you have a pacemaker or a metal implant in the body.
- Prescription medicines: Oral medicines that reduce the nerve signals stimulating the sweat glands, or certain medicines applied to the skin, can be used. They can have side effects such as dry mouth, constipation, blurred vision and difficulty passing urine; they are not suitable with some eye and urinary tract diseases. These medicines should only be used with a physician's prescription and follow-up.
- Botulinum toxin injection: An effective option, especially for underarm and palm sweating. It is described in detail below.
- Device treatments: In the armpits, some device treatments can be used, such as methods that target the sweat glands with microwave energy. Choosing the right person is important.
- Surgery: Local removal of the sweat glands in the armpit or, in severe cases that do not respond to other methods, an operation on the nerve chain through the chest cavity (sympathectomy) may be considered. Sympathectomy is considered a last step; increased sweating in other parts of the body (compensatory sweating) is an important side effect and can be difficult to reverse.
How does botulinum toxin reduce sweating?
Botulinum toxin type A (commonly called “botox”) temporarily blocks the signal travelling from the nerve endings to the sweat glands. As a result, sweating decreases markedly in the treated area. This effect is temporary; as the nerve endings form new connections over time, sweating gradually returns.
Unlike wrinkle treatment, it is not injected into the muscle but just under the skin, into the layer where the sweat glands are, as many small injections. Underarm treatment is one of the most studied and most frequently used applications for excessive sweating.
Who may it be suitable for?
It may be considered for adults with primary focal hyperhidrosis who do not get enough benefit from simple methods such as antiperspirant products, or who cannot tolerate these methods. How much the sweating affects your life is an important criterion in the treatment decision.
Who is it not suitable for, and what should you watch out for?
- Widespread or recently started sweating whose underlying cause has not been investigated
- Pregnancy and breastfeeding
- Active infection or a flare-up of a skin disease in the treatment area
- Diseases affecting muscle and nerve transmission, such as myasthenia gravis
- A history of an allergic reaction to botulinum toxin
- Use of certain medicines with a muscle-relaxing effect and certain antibiotics (be sure to tell your physician)
- For palm treatment: work that relies heavily on manual dexterity or playing a musical instrument (should be discussed beforehand because of the possibility of temporary hand weakness)
Who should perform it, and where?
The assessment of excessive sweating and botulinum toxin treatment should be done by a physician trained in this field, in a licensed healthcare facility that follows hygiene rules. Checking for a secondary cause at the first assessment is an integral part of the treatment.
The product used must be licensed, genuine and stored under appropriate conditions. Products of unknown origin may be ineffective and can also cause serious health problems.
Preparation before the procedure
- Tell your physician when the sweating started, which areas it affects, whether it happens at night and whether there is a similar history in the family.
- Tell them about all the medicines and supplements you take; do not stop your prescription medicines on your own.
- For underarm treatment, if your physician recommends it, remove the hair in the area before the procedure.
- On the day of the procedure, do not apply antiperspirant or deodorant to the area; if your physician has advised otherwise, follow that advice.
- Read the consent form without rushing.
The day of the procedure, step by step
- The physician identifies the area where sweating is most intense. For this, a simple test using iodine and starch that shows the sweating area by a change in colour (the Minor test) may be done.
- The area is marked on the skin and cleaned with an antiseptic solution.
- If needed, an anaesthetic cream or cold application is used. Because palm treatment can be more uncomfortable, additional numbing methods may be discussed.
- Botulinum toxin is injected with a fine needle as many small injections close together in the marked area.
- At the end of the procedure, the area is cleaned; you are given aftercare advice and information on how to reach the physician if there is a problem.
After the procedure: the first 24 hours and the first week
Most people can return to daily life the same day. Not massaging or rubbing the area on the first day is usually recommended. Wait for the period your physician recommends before strenuous exercise, saunas and Turkish baths.
The reduction in sweating usually starts within a few days and becomes noticeable within about two weeks. Assessing the result before this period is over can be misleading.
Expected side effects
- Pain, tenderness or small bruises at the injection points
- Mild redness and swelling
- With palm treatment, temporary weakness of the hand and fingers or difficulty with fine tasks
- In some people, a feeling that sweating has increased slightly outside the treated area
- Rarely, headache or mild flu-like symptoms
These symptoms usually go away within a few days to a few weeks. If you notice anything outside the expected course, see your physician.
If you have any of these symptoms, see a physician without delay; if you have difficulty breathing or swallowing, call 112 (or your local emergency number)
- Difficulty swallowing, speaking or breathing
- Drooping of the eyelid, double vision or widespread muscle weakness
- Shortness of breath, widespread itching or rapidly increasing swelling of the face and tongue (allergic reaction)
- Redness, warmth, pus-like discharge or fever at the injection site that increases over days
- Widespread sweating accompanied by fever, weight loss or night sweats (because of a possible underlying cause)
- Sudden-onset sweating together with chest pain, palpitations or a feeling of fainting
When is the result seen and how long does it last?
The sweat-reducing effect of botulinum toxin is temporary. The duration of the effect varies depending on the person, the treated area and the dose; sources usually report periods from a few months to close to a year. In most people, the effect in the armpits can last longer than on the palms and soles of the feet.
When sweating starts to return, the treatment can be repeated. It is advisable to decide on how often to repeat it and on the overall plan together with your physician.
Realistic expectations: what can treatment not do?
- Botulinum toxin and most other methods do not eliminate excessive sweating completely; the aim is a marked reduction that makes life easier.
- Its effect is temporary; repeat treatment is needed.
- In secondary hyperhidrosis, it does not treat the underlying cause.
- It is effective only in the treated area; it does not reduce sweating over the whole body.
- It does not directly treat sweat odour; however, odour may also decrease as sweating decreases.
Alternatives
| Method | What it does | Point to consider |
|---|---|---|
| Antiperspirant products | The first step for mild to moderate sweating | Can irritate the skin; regular use is needed |
| Iontophoresis | Can be effective especially on the palms and soles of the feet | Regular, ongoing sessions are needed; not suitable in some situations |
| Prescription medicines | Can be used for widespread sweating or sweating in more than one area | Side effects such as dry mouth; only with a physician's follow-up |
| Botulinum toxin | Can markedly reduce sweating in the armpits and on the palms | Its effect is temporary; treatment on the palms is more uncomfortable |
| Device treatments (e.g. microwave) | Target the sweat glands in the armpits | Side effects such as swelling and numbness; choosing the right person is important |
| Surgery (local sweat gland removal, sympathectomy) | In severe cases that do not respond to other methods | With sympathectomy, the risk of compensatory sweating is important |
This page is for general information. The cause of your sweating and the treatment suitable for you can only be determined through a consultation and a physician's assessment.
Aftercare timeline
Treatment day
Do not massage or rub the area. Wait for the period your physician recommends before strenuous exercise, saunas and Turkish baths. If you have difficulty swallowing, speaking or breathing, get emergency help immediately.
Day 1
Mild pain, bruising or redness is expected. Ask your physician when you can start using antiperspirant products again.
Day 4
The reduction in sweating usually starts to be noticed around these days. If you have hand weakness after palm treatment, be careful with fine tasks and tell your physician.
Day 14
The effect has usually become noticeable. Follow-up appointment if your physician recommended one; any small areas where sweating continues are assessed.
Day 90
Watch whether sweating is starting to return; discuss the timing of repeat treatment with your physician.
Questions to ask your physician
- Is my sweating primary, or could there be another cause that needs to be investigated?
- Are there simpler methods I should try before botulinum toxin?
- How much benefit, and for how long, can I expect from underarm (or palm) treatment?
- Would the possibility of hand weakness after palm treatment be a problem for my work?
- Do the medicines I take interact with this treatment?
- Is the product to be used licensed, and can you give me its details in writing?
- How can I reach you if there is a problem?
- Could iontophoresis or medication be a suitable option for me?
Frequently asked questions
Is excessive sweating a disease?
Primary hyperhidrosis is a treatable condition that occurs without another underlying disease. However, sweating that is widespread, occurs at night or has started recently should be investigated by a physician, as it may be a sign of another disease.
Is a deodorant the same as an antiperspirant?
No. A deodorant only reduces odour. Antiperspirant products usually contain aluminium salts and temporarily reduce sweat output.
How long does the effect of botulinum toxin last?
It varies depending on the person and the area; sources usually report periods from a few months to close to a year. In most people, the effect in the armpits can last longer than on the palms.
Does reducing underarm sweating increase sweating elsewhere on the body?
After botulinum toxin treatment, some people may feel that sweating has increased in other areas; this is usually mild. Marked compensatory sweating is a problem associated mainly with sympathectomy surgery.
Is palm treatment painful?
Because the palm is a sensitive area, the treatment can be more uncomfortable than in the armpits. You can talk to your physician about anaesthetic cream, cold application or additional numbing methods.
Is surgery an option?
It may be considered in severe cases that do not respond to other methods. Sympathectomy in particular is considered a last step; because of important side effects such as compensatory sweating, the decision should be made carefully.
Sources
- Hyperhidrosis: Diagnosis and treatment — American Academy of Dermatology (AAD)
- Hyperhidrosis (Patient Information Leaflet) — British Association of Dermatologists (BAD), 2022
- Excessive sweating (hyperhidrosis) — NHS
- The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Etiology and clinical work-up (Nawrocki S, Cha J). J Am Acad Dermatol 81(3):657–666 — Journal of the American Academy of Dermatology, 2019
- The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Therapeutic options (Nawrocki S, Cha J). J Am Acad Dermatol 81(3):669–680 — Journal of the American Academy of Dermatology, 2019
- Hyperhidrosis: Management Options (McConaghy JR, Fosselman D). Am Fam Physician 97(11):729–734 — American Family Physician, 2018
- International Hyperhidrosis Society — International Hyperhidrosis Society
Medical Aesthetics Expert Board
This article has been reviewed by the DoktorClub Medical Aesthetics Expert Board.
