Guide · Hyperhidrosis
Hyperhidrosis when sweating is more than the weather, and how it is treated
In Singapore everyone sweats, but hyperhidrosis is sweating far beyond what heat or exercise explains. Here is how doctors tell primary from secondary hyperhidrosis, which signs need a check-up, how each treatment works, from antiperspirants to surgery, and how to look after underarm skin.
Quick answer
- Hyperhidrosis is sweating well beyond what heat, exercise or nerves explain, often enough to soak clothes or drip from the hands. Primary hyperhidrosis, estimated to affect nearly 3% of people, usually starts before 25, affects both underarms, palms, soles or the face fairly evenly, and stops during sleep; secondary hyperhidrosis is caused by another condition or a medicine.
- See a doctor promptly if you sweat heavily at night, are losing weight without trying, have a fever, or sweat on one side of the body only, or if heavy sweating started suddenly or after about 25. These point to a secondary cause, such as an overactive thyroid, diabetes, menopause, an infection or a medicine, that needs checking.
- Treatment usually goes in steps: a strong aluminium chloride antiperspirant at night, iontophoresis for hands and feet, injections of the medicine used for wrinkle-relaxing injections into the sweating skin, tablets such as glycopyrronium or oxybutynin, and surgery last. Sympathectomy surgery is permanent, and about six in ten people develop compensatory sweating elsewhere afterwards.
- SkinRev Lab is a non-invasive aesthetic centre and does not treat hyperhidrosis, prescribe or inject. It can help with underarm skin that sweat, friction and shaving irritate: waxing at S$38 for women or S$48 for men, GST included, and SKINPINK brightening at S$288 per region before GST. For medical treatment, see your GP, a dermatologist or Dr Sin Yong at IN Eternity Clinic, who can advise whether a treatment suits you; medical care is priced at consultation.
The basics
What hyperhidrosis is, and why it is more than Singapore sweat
Everyone in Singapore sweats. Sweat is how the body sheds heat, and in a hot, humid city a damp shirt after the walk from the MRT is normal. Hyperhidrosis is different: sweating beyond what the body needs to stay cool, often in an air-conditioned room or at rest, in amounts that soak through clothes, drip from the fingers or smudge paper.
Doctors divide it into two kinds. Primary, or focal, hyperhidrosis has no underlying disease. It mostly affects areas packed with eccrine sweat glands, namely the underarms, palms, soles and face, and a 2011 review estimated it affects nearly 3% of people. Secondary hyperhidrosis is caused by something else, such as a medicine, a hormonal change, an infection or another medical condition, and is often more widespread.
Hyperhidrosis is not about hygiene or fitness, and primary hyperhidrosis is not dangerous in itself. It can still affect work, handshakes, holding a phone and what you wear. It also keeps skin damp, which can encourage rashes, fungal and bacterial infections and irritation, especially in the underarms.
Primary vs secondary
Primary vs secondary hyperhidrosis: how doctors tell them apart
In a review of 415 people seen for hyperhidrosis at a university dermatology department, 93% had the primary type. People with secondary hyperhidrosis were older on average (39 compared with 27), and more than half of them had started sweating heavily after the age of 25, against 12% of those with primary hyperhidrosis.
From that study, the author proposed criteria for primary hyperhidrosis: excessive sweating for six months or more, with at least four of the following. It mainly affects the underarms, palms, soles or face; it is on both sides and fairly symmetrical; it does not happen at night; episodes happen at least weekly; it began at 25 or younger; there is a family history; and it gets in the way of daily life.
| Primary hyperhidrosis | Secondary hyperhidrosis | |
|---|---|---|
| Cause | No underlying disease; often runs in families | Another condition or a medicine |
| Usual start | Childhood or the teens; usually by 25 | Any age; more often later in life |
| Where | Underarms, palms, soles or face | Often larger areas or the whole body |
| Pattern | Both sides, fairly evenly | Can be one-sided or patchy |
| At night | Usually stops during sleep | Can happen during sleep (night sweats) |
| First step | Treatment in steps, starting with antiperspirant | Find and treat the cause |
See a doctor
When to see a doctor about sweating
Heavy sweating that started in your teens and affects both underarms or both palms is usually primary hyperhidrosis. Some patterns need a doctor's check first, because the sweating may be a sign of something else.
A GP is a sensible first stop. They will ask when it started, where it happens and whether it happens at night, and may check your blood pressure, blood sugar and thyroid function. Causes of generalised sweating listed by dermatologists include obesity, diabetes, menopause, an overactive thyroid, heart and lung conditions, some medicines and, rarely, lymphoma. Seek urgent care for sweating with chest pain, breathlessness or fainting.
- Sweating at night that soaks your sheets or nightwear.
- Losing weight without trying, a fever, or feeling generally unwell.
- Sweating on one side of the body only, or in one patch.
- Heavy sweating that started suddenly, or for the first time after about 25.
- A racing heart, a tremor, always feeling hot or new anxiety, which can point to an overactive thyroid.
- Sweating with shakiness or hunger if you have diabetes, which can be low blood sugar.
- Sweating that began after starting a new medicine; do not stop a prescribed medicine without advice.
- Hot flushes and night sweats around the menopause.
Treatment options
Hyperhidrosis treatment in Singapore, step by step
A 2011 review proposed a treatment ladder for each body site. For underarm sweating it put topical treatment first, injections second, tablets third, local surgery fourth and sympathectomy last. For palms and soles it placed tablets and iontophoresis before injections, and for facial sweating it started with tablets. A doctor adjusts the order to your situation, and the review's authors note that in most cases treatment can be tailored to give a satisfactory outcome.
| Treatment | Mainly used for | Points to know |
|---|---|---|
| Aluminium chloride antiperspirant at night | Underarms, palms, soles | Usual first step; stinging and irritation are common at first |
| Iontophoresis (a weak current through water) | Palms and soles | Frequent sessions at first, then maintenance; home devices exist |
| Injections into the sweating skin | Underarms; sometimes palms | Same medicine as wrinkle-relaxing injections; lasts months; repeated |
| Tablets such as glycopyrronium or oxybutynin | Face, widespread sweating, or when other steps fail | Prescription only; dry mouth is common |
| Local removal or destruction of sweat glands | Underarms | Surgical or device-based procedures done by doctors |
| Endoscopic thoracic sympathectomy (ETS) | Severe palm, underarm or facial sweating | Permanent; compensatory sweating elsewhere is common |
Antiperspirants
Aluminium chloride antiperspirants: how to use them properly
Deodorants mask odour; antiperspirants reduce sweat by plugging the sweat ducts with aluminium salts. Everyday antiperspirants contain roughly 10% to 25% aluminium salts, and stronger aluminium chloride solutions are sold in pharmacies; a pharmacist or doctor can advise which strength to start with. They are the usual first treatment for underarms, palms and soles.
How you apply it matters more than which brand you buy. Antiperspirant works better when the sweat glands are quiet, so it goes on completely dry skin at night, not in the morning rush. Many people use it nightly at first, then cut down to once or twice a week once sweating is under control.
- Apply to clean, completely dry skin at bedtime, after a cool shower.
- Wash it off in the morning; a normal deodorant is fine during the day.
- Do not apply it to freshly shaved or waxed skin, or to broken or inflamed skin; wait a day or two.
- If it stings or itches, use it less often or wash it off sooner, and ask a pharmacist or doctor if irritation continues.
- Give it a few weeks of regular use before deciding it has not worked.
Iontophoresis
Iontophoresis for sweaty palms and feet
Iontophoresis passes a gentle electric current through water into the skin, usually with the hands or feet resting in shallow trays. It is thought to block the sweat ducts temporarily. Sessions last about 10 to 20 minutes and are repeated daily, or several times a week, for a few weeks, then less often to keep the effect.
It is used mainly for palms and soles, where antiperspirants tend to work less well, and some doctors add a glycopyrronium solution to the water for a stronger effect. Tingling and dry skin are common. Once a doctor has shown you how, machines for home use are available. If you have a pacemaker or other implanted device, or are pregnant, ask a doctor before trying it.
Injections
Injections for underarm sweating
The neuromodulator used in wrinkle-relaxing injections also blocks the nerve signal that switches sweat glands on. For underarm sweating, a doctor places many small injections just under the skin across the sweating area, which is often mapped first with a simple starch-iodine test. The effect starts within days and lasts several months, so treatment is repeated when sweating returns.
In a trial of 145 people with severe underarm sweating, one underarm was injected and the other received a placebo. Two weeks later, sweat production in the treated underarm averaged 24 mg a minute, against 144 mg on the placebo side, from an average of 192 mg at the start. Dermatology references describe the effect as lasting three to six months. Injections into the palms are also used but are more painful.
This is a prescription medical treatment that only a doctor should give. SkinRev Lab does not inject. IN Eternity Clinic's wrinkle-relaxing injections page explains how the medicine works for expression lines; whether underarm injections suit your sweating is something a doctor can advise after assessing you.
Tablets
Oral medicines for hyperhidrosis
When sweating is widespread, affects the face, or has not responded to other steps, a doctor may prescribe tablets that block the chemical signal to the sweat glands. Glycopyrronium (also called glycopyrrolate) and oxybutynin are the most used; clonidine is another option. Because they act on the whole body, they can help several areas at once.
In a randomised, placebo-controlled trial of 50 people, more than 70% of those on low-dose oxybutynin reported improvement in palm and underarm sweating after six weeks; dry mouth affected about half (47.8%). Other side effects of this group of medicines include constipation, blurred vision and difficulty passing urine. Because they reduce sweating, they can also make overheating more likely during exercise in hot weather, which matters in Singapore.
These are prescription medicines and are not suitable for everyone, for example people with some types of glaucoma, so a doctor checks your health and other medicines first. SkinRev Lab does not prescribe.
Surgery
Surgery, sympathectomy and compensatory sweating
For the underarms, doctors can remove or destroy sweat glands locally, by cutting them out, by suction curettage, or with devices that heat the glands using microwave or laser energy. These are medical procedures with their own risks, such as scarring and infection, and are usually considered after the steps above. SKINSHAPE at SkinRev Lab also uses microwave energy, but it is a body-contouring treatment for fat, including armpit fat, and is not designed to treat sweating.
Endoscopic thoracic sympathectomy (ETS) cuts or clips part of the sympathetic nerve chain inside the chest through keyhole surgery. It is used for severe palm, underarm and facial sweating, but it is permanent. The main drawback is compensatory sweating: new or heavier sweating on the back, chest, abdomen or legs. A 2025 meta-analysis of ten studies and 3,117 patients found it in about 62% of people after sympathectomy, and severe compensatory sweating in about 23%; older age, higher body weight and smoking raised the risk.
Because compensatory sweating can be more troublesome than the original problem and cannot be reliably undone, dermatology references keep sympathectomy for the most severely affected people. It is worth a frank discussion with a thoracic surgeon, and trying the other steps first, before deciding.
Underarm care
Looking after underarm skin when you sweat a lot
Constant moisture, friction and frequent shaving are hard on underarm skin, and many people with heavy underarm sweating also notice darkening, bumps or rashes. Removing hair does not reduce how much the glands produce, but gentler hair removal can cut down the irritation that adds to darkening, and keeping the skin dry helps prevent fungal and bacterial problems.
At SkinRev Lab, CityLink Mall #B1-28, an underarm wax is S$38 for women and S$48 for men, GST included, with a first-visit rate of S$28. For flat darkening linked to shaving and friction, SKINPINK is a needle-free brightening session at S$288 per region before GST, or S$88 for one region on a first visit; a course is planned at assessment and results vary. Velvety, thickened underarm skin should be checked by a doctor first. SkinRev Lab does not diagnose or treat hyperhidrosis.
- Wear loose, breathable fabrics and change out of damp clothes after the commute or the gym.
- Pat the area dry rather than rubbing it; sweat pads in shirts can help on work days.
- Choose fragrance-free products when the skin is irritated.
- After a wax, leave antiperspirant and deodorant off for the rest of the day, and skip the gym, sauna and hot showers for 24 hours.
- See a doctor for an itchy, spreading rash, or for painful lumps or boils in the armpits, which can be infection or hidradenitis suppurativa.
Sources
References & sources
- Walling HW. Clinical differentiation of primary from secondary hyperhidrosis. J Am Acad Dermatol. 2011;64(4):690-695.
- Walling HW, Swick BL. Treatment options for hyperhidrosis. Am J Clin Dermatol. 2011;12(5):285-295.
- Heckmann M, Ceballos-Baumann AO, Plewig G; Hyperhidrosis Study Group. Botulinum toxin A for axillary hyperhidrosis (excessive sweating). N Engl J Med. 2001;344(7):488-493.
- Wolosker N, de Campos JR, Kauffman P, Puech-Leão P. A randomized placebo-controlled trial of oxybutynin for the initial treatment of palmar and axillary hyperhidrosis. J Vasc Surg. 2012;55(6):1696-1700.
- Lin ZY, Lin M. Which patients are more likely to experience compensatory hyperhidrosis after endoscopic thoracic sympathectomy: a meta-analysis and systematic review. PeerJ. 2025;13:e19097.
- Oakley A. Hyperhidrosis (excessive sweating). DermNet (dermnetnz.org).
- NHS. Excessive sweating (hyperhidrosis). NHS website. Last reviewed 7 November 2023.
Common questions
Your questions,
answered
What causes hyperhidrosis?
In primary hyperhidrosis the sweat glands are normal but the nerves that switch them on appear to be overactive, and it often runs in families. Secondary hyperhidrosis is caused by something else, such as a medicine, an overactive thyroid, diabetes, menopause, an infection or, rarely, lymphoma.
Is hyperhidrosis a serious condition?
Primary hyperhidrosis is not dangerous, but it can affect work, social life and confidence, and it is treatable. Sweating that is new, happens at night, comes with weight loss or fever, or affects one side only should be checked by a doctor, because it can be a sign of another condition.
Which treatment works for underarm sweating?
Most people start with an aluminium chloride antiperspirant applied at night to completely dry skin. If that is not enough, injections into the underarm skin, given by a doctor, reduce sweating for several months. Tablets, local procedures and, last of all, sympathectomy are further options.
Does aluminium chloride work for hyperhidrosis?
Often, yes, especially for the underarms. Apply it to completely dry skin at bedtime and wash it off in the morning, nightly at first and then once or twice a week. Irritation is the main side effect, so avoid freshly shaved or waxed skin.
How long do injections for sweating last?
Usually three to six months, after which sweating gradually returns and the treatment is repeated. It is a prescription treatment that only a doctor should give, and a doctor can advise whether it suits you.
What is compensatory sweating after ETS?
It is new or heavier sweating on other areas, usually the back, chest, abdomen or legs, after sympathectomy surgery. A 2025 meta-analysis found it in about 62% of patients, and in a severe form in about 23%. Because the surgery is permanent, it is usually kept for severe cases.
Does hyperhidrosis go away?
Primary hyperhidrosis is usually long-term, but a treatment plan matched to the area affected controls it satisfactorily for most people. Secondary hyperhidrosis often improves once its cause, such as a medicine or a thyroid problem, is found and treated.
Who treats hyperhidrosis in Singapore?
A GP is a good first stop and can start treatment and check for causes. Dermatologists manage hyperhidrosis, and thoracic surgeons perform sympathectomy. Dr Sin Yong at IN Eternity Clinic can see you for a consultation and advise whether a treatment suits you. SkinRev Lab does not treat hyperhidrosis but offers underarm waxing and brightening.