Quick answer

Why do I sweat so much?

Sweating heavily is often normal — heat, exercise, stress, spicy food, caffeine and being overweight all play a part, and some people simply sweat more. Antiperspirant (not deodorant), loose clothing and avoiding triggers help. See your GP if sweating soaks your clothes or bedding at night, starts suddenly, or comes with weight loss, fever or palpitations, as these need checking.

Normal sweating vs excessive sweating

Sweating is how your body sheds heat — during exercise, hot weather, stress, or after caffeine, alcohol or spicy food. How much you sweat varies enormously between people, and sweating a lot is not automatically a problem.

It becomes excessive sweating (hyperhidrosis) when it regularly soaks clothes, drips, or interferes with daily life without a matching trigger. That pattern most often affects the armpits, palms, soles and face.

Common causes

  • Primary hyperhidrosis — overactive sweat signalling, often starting young and running in families; not caused by illness
  • Weight — carrying more weight increases sweating at any temperature
  • Hormones — menopause hot flushes, and an overactive thyroid
  • Anxiety and stress — sweating is part of the fight-or-flight response
  • Medicines — some antidepressants, painkillers and diabetes medicines
  • Alcohol, caffeine and spicy food
  • Low blood sugar and infections

What actually helps

  1. Switch to an antiperspirant — deodorants mask smell; antiperspirants block sweat. Aluminium chloride products are the strongest — apply at night to completely dry skin, wash off in the morning.
  2. Dress for it — loose fits, natural or sports moisture-wicking fabrics, dark colours or patterns that hide damp.
  3. Trim the triggers — caffeine, alcohol, spicy food, and stress where you can.
  4. Ask a pharmacist — stronger antiperspirants and practical advice are available without a prescription.
  5. See a GP if it persists — options include prescription antiperspirants, iontophoresis (a mild electrical treatment for hands and feet), botulinum toxin injections for armpits, and occasionally tablets that reduce sweating.

Sweating that needs a GP check

Most heavy sweating is benign, but see a GP if sweating starts suddenly, affects one side only, drenches bedding at night, or comes with weight loss, fever, swollen glands or palpitations — see our guide to night sweats for what those patterns can mean.

Common questions about excessive sweating

What is hyperhidrosis?
Hyperhidrosis is sweating that is excessive for the situation — often affecting the armpits, palms, soles or face, without an obvious trigger. Primary hyperhidrosis usually starts in childhood or the teens, often runs in families, and is caused by overactive sweat signalling rather than illness. It is common, and effective treatments exist, so it is worth raising with a pharmacist or GP.
How can I stop sweating so much?
Use an antiperspirant rather than a deodorant — ideally one with aluminium chloride, applied at night to dry skin. Wear loose, natural or moisture-wicking fabrics, and cut down triggers such as caffeine, alcohol and spicy food. If that is not enough, a GP can offer prescription options, iontophoresis, botulinum toxin injections for armpit sweating, or in some cases tablets.
Why do I sweat so much at night?
A warm room or heavy bedding is the usual reason — but drenching night sweats that soak nightclothes or sheets need a GP review. Common causes include menopause, anxiety, alcohol, low blood sugar and medicines such as some antidepressants. Infections and, rarely, blood cancers can also cause them, especially with fever, weight loss or swollen glands.

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