Excessive sweating

Sweating is how the body cools itself, but some people sweat far more than is needed. It helps to separate two patterns. Primary (focal) hyperhidrosis is a common, harmless tendency to sweat excessively in specific areas — palms, soles, underarms or face — usually starting young, running in families, and not due to any disease; it is a nuisance rather than a warning sign. Generalised or secondary sweating — sweating all over, or that is new, or that drenches you at night — is more likely to reflect an underlying cause and is worth attention. Common causes include an overactive thyroid (hyperthyroidism), which speeds up the metabolism and often adds weight loss, a racing heart and tremor; the menopause, where hot flushes and night sweats are typical; low blood sugar (hypoglycaemia), especially in someone treated for diabetes, which causes sudden sweating, shakiness and hunger; infections, which cause fevers and sweats; and certain medications, anxiety and, less commonly, hormone-producing tumours. Drenching night sweats, particularly with unexplained weight loss, fevers or swollen glands, are a recognised warning combination that needs assessment, as they can occasionally signal a serious condition such as a lymphoma or chronic infection.

• Primary (focal) hyperhidrosis — a harmless localised tendency (palms, underarms, soles), often lifelong.
• Overactive thyroid (hyperthyroidism) — with weight loss, racing heart and tremor.
• Menopause — hot flushes and night sweats.
• Low blood sugar (hypoglycaemia) — sudden sweating with shakiness and hunger, especially in treated diabetes.
• Infection — fever and sweats.
• Medications, anxiety, alcohol or caffeine.
• Drenching night sweats with weight loss or fever — a warning combination that can point to lymphoma or chronic infection.

For localised, lifelong sweating with no other symptoms, no tests are usually needed. For generalised, new, or night sweating, blood tests help look for a cause: thyroid function (TSH and free T4) for an overactive thyroid, glucose or HbA1c and — in treated diabetes — attention to hypoglycaemia, a full blood count and inflammatory markers for infection or, with other warning signs, blood cancers. In a woman of the right age, the pattern of hot flushes and night sweats usually points to the menopause without needing hormone tests. Mediora.AI can surface a thyroid or glucose pattern that explains excessive sweating, but drenching night sweats — especially with weight loss, fever or swollen glands — need proper clinical assessment by your doctor.