How to treat excessive sweating

The short answer: excessive sweating (hyperhidrosis) is a real medical condition, and it is very treatable. Most people start with a strong aluminium chloride antiperspirant. If that isn’t enough, injections of botulinum toxin into the underarms reduce sweating dramatically for most people, with each treatment lasting around 4 to 9 months. Iontophoresis works well for the hands and feet, and tablets or, rarely, surgery are options for more severe cases. Sweating that starts suddenly in adulthood, affects your whole body or soaks you at night should be checked by your GP first.

People with hyperhidrosis often tell me they’ve spent years planning their lives around it: only wearing black or white, keeping their arms clamped to their sides in meetings, avoiding shaking hands, carrying a spare shirt everywhere. Many assume it’s just how they are, or feel too embarrassed to mention it to a doctor. It’s far more common than most people realise, and there’s a lot that can be done. In this article I explain what causes it, how to tell whether it’s hyperhidrosis or something else, and the treatments that work, from the simplest upwards.

What is hyperhidrosis?

Sweating is how the body keeps cool. Hyperhidrosis means sweating far more than the body needs to control its temperature, often when you are cool and resting.

There are two types:

• Primary (focal) hyperhidrosis is the common type. It affects particular areas, usually the underarms, palms, soles of the feet or face and scalp, on both sides. It usually starts in childhood or the teenage years, often runs in families, and tends to stop during sleep. The sweat glands are normal; the nerves that switch them on are overactive.
• Secondary hyperhidrosis is caused by something else, such as the menopause, an overactive thyroid, diabetes, an infection, some medicines (including certain antidepressants) or, rarely, a more serious illness. It is more likely to start in adulthood, affect the whole body, or happen at night.

Studies in different countries suggest that around 1 to 5 in every 100 people have primary hyperhidrosis. Fewer than half of them ever talk to a doctor about it.

“I often hear ‘I didn’t think it was something a doctor could help with.’ It is. Hyperhidrosis is a medical condition, and treating it can change how someone lives day to day.”

Mr Siva Kumar, consultant plastic surgeon

How do I know if my sweating is excessive?

There’s no blood test for hyperhidrosis. It’s diagnosed on how much the sweating affects your life. Doctors often use a simple four-point scale:

1. My sweating is never noticeable and never interferes with my daily activities.
2. My sweating is tolerable but sometimes interferes with my daily activities.
3. My sweating is barely tolerable and frequently interferes with my daily activities.
4. My sweating is intolerable and always interferes with my daily activities.

If you’d answer 3 or 4, your sweating is considered severe, and treatment beyond normal antiperspirants is reasonable.

When should I see my GP first?

Please see your GP before having any cosmetic treatment if your sweating:

• started in adulthood with no obvious trigger
• affects your whole body, or only one side
• happens mainly at night and soaks your bedclothes
• comes with weight loss, fever, a racing heart, or feeling generally unwell
• began after starting a new medicine

These can point to secondary hyperhidrosis, where treating the cause is the answer.

What is the best treatment for excessive sweating?

Treatment works best as a step-by-step ladder, starting with the simplest options. UK guidance for GPs and dermatologists broadly follows this order.

Step 1: A strong antiperspirant

Ordinary deodorants mask smell; antiperspirants reduce sweat. The most effective over-the-counter option contains aluminium chloride hexahydrate, usually at 20%, which plugs the sweat ducts. To get the best from it:

• apply it at night, to completely dry skin, when the sweat glands are least active
• wash it off in the morning
• use it every night at first, then reduce to once or twice a week once sweating is under control
• give it at least six weeks before deciding it hasn’t worked

The main problem is skin irritation, which can often be eased with a mild steroid cream or by using it less often. It works well for many people with underarm sweating, but it is less effective and often too irritating for the palms and soles.

Step 2: Botulinum toxin injections (best for underarms)

If a strong antiperspirant hasn’t been enough, injections of botulinum toxin are one of the most effective treatments available, particularly for the underarms. The same prescription medicine used to soften frown lines blocks the nerve signal that switches on the sweat glands.

The evidence is strong. In two large randomised trials published in 2001, in the New England Journal of Medicine and the BMJ, more than 90% of people with severe underarm sweating responded to treatment, with sweat production falling by around 80% or more. Benefits typically last 4 to 9 months, and sometimes longer.

• Treatment time: about 30 minutes. Tiny injections are placed just under the skin across the sweating area, which I map out first.
• When it works: within 2 to 7 days, with the full effect at around two weeks.
• How often: usually every 4 to 9 months, once sweating starts to return.
• Downtime: none. Most people go straight back to their day.
• Side effects: mild and short-lived, such as tenderness or a small bruise.

Injections can also treat the palms, but they are more uncomfortable there, usually needing a nerve block or numbing, and can temporarily weaken grip. I talk this through carefully before treating hands.

“For underarm sweating, injections are one of the most satisfying treatments I offer. People come back after two weeks and tell me they wore a grey shirt for the first time in years.”

Mr Siva Kumar

Step 3: Iontophoresis (best for hands and feet)

Iontophoresis involves placing your hands or feet in shallow trays of tap water while a gentle electrical current passes through them. It isn’t fully understood how it works, but it reduces sweating in most people with sweaty palms and soles. Sessions take 20 to 30 minutes, several times a week at first, then less often to maintain the effect. Home machines are available, and some NHS dermatology departments offer it.

Step 4: Tablets

Medicines that block the chemical messenger switching on sweat glands, such as oxybutynin or propantheline, can reduce sweating all over the body. They’re useful when sweating affects several areas. Side effects such as a dry mouth, blurred vision and constipation limit them for some people, and they aren’t suitable for everyone, especially older people. Your GP or dermatologist can advise.

Step 5: Procedures and surgery

• Microwave treatment of the underarms uses heat to destroy sweat glands permanently. NICE guidance says it should be used only with special arrangements for consent and audit, as evidence on long-term safety is still limited.
• Local surgery to remove or scrape out underarm sweat glands can help in selected cases, but it leaves scars and isn’t commonly needed now.
• Endoscopic thoracic sympathectomy (ETS) cuts or clamps the nerves that control sweating in the hands. It’s a last resort. Many people develop heavier “compensatory” sweating on the back, chest or legs afterwards, which can be worse than the original problem and is often permanent.

Is it safe to stop my underarms sweating?

Yes. Your underarms contain only a small share of your body’s sweat glands, so treating them doesn’t affect your ability to keep cool. Injections don’t cause heavier sweating elsewhere. That’s different from ETS surgery, where compensatory sweating is a real risk.

How can I manage sweating day to day?

• Clothing: loose, breathable natural fabrics, or technical sports fabrics that wick moisture away. White and black show marks less than grey and pale blue.
• Sweat pads stuck inside clothing can protect shirts and give confidence on important days.
• Feet: leather or canvas shoes rather than synthetic ones, cotton or wicking socks changed during the day, and alternating pairs of shoes so they dry out.
• Triggers: heat, spicy food, alcohol, caffeine and stress make sweating worse for some people. Breathing techniques before stressful situations can help.
• Support: the charity Hyperhidrosis UK has practical advice and a community of people who understand.

Hyperhidrosis has a real effect on mental health. Many people with it describe anxiety or low mood, and social anxiety can make the sweating worse. If that’s you, mention it to your GP, as treating both together often helps most.

Is hyperhidrosis treatment available on the NHS or with insurance?

On the NHS, strong antiperspirants and tablets are usually available through your GP. Iontophoresis and injections are offered by some dermatology departments for severe cases that haven’t responded to first-line treatment, though availability varies by area.

Privately, because hyperhidrosis is a medical condition, some insurers cover treatment, so check your policy. Self-pay underarm treatment with me starts from £495 at The Ü Clinic in Sevenoaks and Oxted. You can read more on my hyperhidrosis treatment page.

Quick questions

Do the injections hurt?

The needles are very fine, and most people find underarm treatment very manageable. A numbing cream can be used if you are worried.

How long do sweating injections last?

Usually 4 to 9 months for the underarms. Some people find each treatment lasts a little longer than the last.

Can I use antiperspirant after treatment?

Yes, but most people find they no longer need a strong one. Avoid applying it on the day of treatment.

Can children and teenagers be treated?

Hyperhidrosis often starts in the teenage years. Strong antiperspirants and iontophoresis can be used in younger people. Injections for medical reasons in under-18s should be arranged through a specialist, usually on the NHS.

Does excessive sweating ever go away on its own?

Primary hyperhidrosis often improves a little with age, but for most people it continues for many years without treatment.

Does hyperhidrosis cause body odour?

Not directly. Sweat itself has no smell; odour comes from bacteria breaking down sweat from a different type of gland. Keeping the area dry often reduces odour too.

Next steps

If sweating is affecting your life, please don’t just put up with it. You can book a consultation at The Ü Clinic in Sevenoaks or Oxted, and we’ll work out the best treatment for you.

Sources

• Heckmann M, et al. Botulinum toxin A for axillary hyperhidrosis (excessive sweating). New England Journal of Medicine 2001;344:488–93. doi:10.1056/NEJM200102153440704
• Naumann M, Lowe NJ. Botulinum toxin type A in treatment of bilateral primary axillary hyperhidrosis: randomised, parallel group, double blind, placebo controlled trial. BMJ 2001;323:596. doi:10.1136/bmj.323.7313.596
• NICE Clinical Knowledge Summaries. Hyperhidrosis. cks.nice.org.uk
• NICE. Transcutaneous microwave ablation for severe primary axillary hyperhidrosis. Interventional procedures guidance IPG601, 2017.
• Hyperhidrosis UK. hyperhidrosisuk.org