THE SKIN EDIT · CONDITION FOCUS
Excessive Sweating: Causes, When to Get It Checked and What the Options Are
Most people sweat more in heat, in a stressful meeting, halfway through a spin class. That is your system working.
Hyperhidrosis is different. It is sweating beyond what the body needs for temperature control. It may happen without an obvious trigger or be far heavier than the temperature, activity or situation would normally explain. It can soak through clothing, disrupt work and affect clothing choices, social situations and confidence. Indeed, a surprising number of people live with it for years before anyone tells them it has a name.
It is more common than most people assume, and it is treatable. Here is what is actually going on.
What is hyperhidrosis?
Excessive sweating that goes beyond what the body needs for temperature control. It is a recognised medical condition rather than a hygiene problem or a symptom of nerves, and it is usually divided into primary and secondary forms.
Primary hyperhidrosis usually starts in adolescence or early adulthood, tends to affect specific areas rather than the whole body, and often runs in families. The underarms, palms, soles and face are the most commonly affected.
Secondary hyperhidrosis often comes on later, is often more generalised, and happens because of something else: an underlying condition, a hormonal change, or a medication side effect. The distinction matters, because secondary hyperhidrosis needs the underlying cause looked at rather than the sweating treated in isolation.
What causes excessive sweating?
In primary hyperhidrosis the sweat glands themselves are normal. The nerve signal reaching them is overactive. Why that happens is not fully established, though there is a clear genetic component in many cases.
That is worth understanding, because it explains why stronger deodorant so often fails. Deodorant addresses odour. Antiperspirant reduces sweat at the surface. Neither touches the signal that is switching the glands on in the first place.
It also explains why the sweating is not proportionate to how hot or anxious you are. The trigger is not the situation.
When is sweating a medical concern rather than a nuisance?
When it is new, when it is generalised rather than localised, when it happens at night, or when it comes alongside other symptoms. Any of those points towards secondary hyperhidrosis and needs proper assessment rather than treatment of the sweating alone.
Specifically, speak to a doctor rather than seeking cosmetic treatment if:
- The sweating has started recently, particularly in mid-life or later, having never been a problem before.
- It affects your whole body rather than specific areas.
- You are sweating heavily at night.
- It comes with weight loss, fever, palpitations, or feeling generally unwell.
- It began after starting a new medication.
- It is on one side of the body only.
None of these necessarily means that something serious is wrong, but they can suggest a secondary cause and should be assessed before the sweating is treated in isolation. Your GP is the appropriate first step.
Is it the same as sweating when you are nervous?
No, although anxiety can trigger or worsen sweating, and the two can reinforce each other. In primary hyperhidrosis, the amount of sweat is disproportionate to what the situation requires and may occur without an obvious emotional trigger.
People can then become anxious about visible sweating, which may intensify it further. This loop is one reason many delay seeking help: they assume that being less anxious would solve the problem and that the sweating is something to manage privately rather than treat.
Addressing anxiety may help when it is present, but it does not necessarily address the underlying hyperhidrosis.
What treatment options are available?
Several, and they escalate. Most people start with a clinical-strength topical, and which option suits depends on the area affected, how severe it is, and what has already been tried.
Clinical-strength topical antiperspirants
Preparations containing aluminium chloride work at the surface by blocking the sweat ducts, and they are the first step for most people. They are widely available, they are inexpensive, and for a proportion of people they are enough. The main limitation is skin irritation, which is what tends to end their use.
Iontophoresis
Iontophoresis passes a mild electrical current through water to the affected area and is most commonly used for the palms and soles. It usually requires an initial course followed by maintenance treatment. Home devices are available, but suitability and safe use should be discussed with an appropriate healthcare professional, particularly if you are pregnant or have an implanted electrical device or certain metal implants.
Oral medication
Certain prescription tablets reduce sweating throughout the body. Because the effect is systemic rather than local, side effects are the limiting factor and they are not suitable for everyone. This is a prescription decision made after assessment, not something to source independently.
A prescription-only injectable option
For localised sweating, particularly in the underarms, there is a prescription-only injectable treatment that interrupts the nerve signal reaching the sweat glands. It is prescription-only for good reason, it is assessed individually at consultation, and it is not suitable for everyone. We can talk through whether it is appropriate for you, alongside the other options above.
Surgical options
For severe cases that have not responded to anything else, surgical approaches exist. They are a specialist referral rather than something offered here, and they are reserved for a small minority because they carry meaningful risks, including compensatory sweating elsewhere on the body.
Does treatment stop it coming back?
Mostly no, and it is better to think of hyperhidrosis as managed rather than cured. Topicals need continued use, iontophoresis needs maintenance, oral medication works while it is being taken, and the injectable option is temporary and would need repeating.
That sounds discouraging written down but it is not, in practice. People who find something that works for them generally describe the difference as substantial, and the practical question becomes which form of ongoing management fits their life rather than whether the problem is solved permanently.
What does change the outlook is getting the assessment right at the start, particularly in ruling out secondary causes.
What does not help
- Stronger deodorant. It addresses odour, not sweating, and they are different problems.
- Relying indefinitely on it settling by itself. Symptoms can change over time, but persistent sweating that affects daily life deserves assessment.
- Managing it entirely through clothing choices. Understandable, but it is not a treatment.
- Assuming it is anxiety and treating only that. Worth addressing if it is present, but in primary hyperhidrosis it is usually the consequence rather than the cause.
Where to start
If the sweating is longstanding, affects specific areas, and has been there since your teens or twenties, that pattern points to primary hyperhidrosis and it is worth having assessed properly rather than continuing to work around it.
If it is new, generalised, or comes with anything else, start with your GP so the underlying cause gets looked at first.
For the first of those, arrange a consultation and we will work out what is driving it and which of the options above is appropriate for you.
As with any medical treatment, individual results and experiences vary, and suitability, risks and alternatives are discussed fully at consultation.
Where to find us
The clinic is at 120 Pall Mall, St James’s, central London SW1Y 5EA, a short walk from Piccadilly Circus, Green Park and Charing Cross.
We see patients from across central London and the surrounding areas. Assessment comes first, and what happens after that depends on what the assessment finds.
Frequently asked questions
What is hyperhidrosis?
Excessive sweating that goes beyond what the body needs for temperature control. It is a recognised medical condition rather than a hygiene problem, and it is divided into primary hyperhidrosis, which usually starts in adolescence and affects specific areas, and secondary hyperhidrosis, which is caused by something else.
Why do I sweat so much even when I am not hot or stressed?
In primary hyperhidrosis the sweat glands are normal but the nerve signal switching them on is overactive. That is why the sweating is not proportionate to the temperature or the situation, and why stronger deodorant does not help.
When should I see a doctor about excessive sweating?
If the sweating is new, affects your whole body, happens at night, occurs on one side only, began after starting a medication, or comes with weight loss, fever or feeling unwell. Those point towards a secondary cause that needs assessing first.
What treatments are available for excessive sweating?
They escalate. Clinical-strength topical antiperspirants containing aluminium chloride are the first step for most people, followed by iontophoresis for palms and soles, oral medication where a systemic effect is appropriate, and a prescription-only injectable option for localised sweating. Surgery is reserved for severe cases.
Can hyperhidrosis be cured?
It is managed rather than cured. Topicals need continued use, iontophoresis needs maintenance, oral medication works while it is taken, and the injectable option is temporary and repeated. Most people find the difference substantial even so.
Where is Dr Nabil Jetha’s clinic?
The clinic is at 120 Pall Mall, St James’s, London SW1Y 5EA, in central London. It is a short walk from Piccadilly Circus, Green Park and Charing Cross, and easily reached from across the West End and the City.
If the sweating is longstanding and affects specific areas, the next step is a proper assessment before anything is decided.
Written and edited by Dr Nabil Jetha and his clinic team. Dr Nabil Jetha, MBBS, BSc (Hons), PGDip (Aesthetics), GMC 7751313, central London. For educational purposes only; individual results vary and any treatment depends on personal assessment.