Concise answer
Sweating deserves medical assessment when it starts suddenly, occurs during sleep, affects the whole body or is accompanied by fever, weight change, palpitations, weakness or a medicine change.
Long-standing sweating limited to palms, soles or underarms can follow a different pattern from new generalised sweating.
The history helps determine whether symptom control or investigation of an underlying factor should come first.
When evaluation may help
Seek prompt care for sweating with chest pain, faintness, breathing difficulty or severe illness; otherwise arrange review when it disrupts daily life.