What Causes Excessive Sweating?

Primary hyperhidrosis usually affects specific areas such as the palms, soles, underarms, or face. It can happen while the person is awake and may interfere with writing, handling objects, clothing, or social situations. Secondary sweating can affect more of the body or begin later in life. Possible contributors include fever, menopause, thyroid overactivity, low blood sugar, infection, some medicines, alcohol, and sleep-related breathing problems.

The timing matters. Sweating during sleep, sweating with weight change or racing heartbeat, or a new change after starting a medicine deserves clinical review. Sweating by itself does not identify one diagnosis, so a clinician may ask about triggers, body areas, medicines, family history, and associated symptoms.

Keep a brief record of when sweating happens, where it occurs, possible triggers, and any dizziness, tremor, palpitations, thirst, fever, or sleep disruption. Use breathable clothing, change damp garments, and consider a suitable antiperspirant used as directed. A clinician can check for an underlying cause and discuss options such as prescription products, iontophoresis, botulinum toxin injections, or microwave sweat-gland treatment when appropriate.

Seek urgent help if heavy sweating occurs with chest pain, shortness of breath, fainting, confusion, severe weakness, or signs of low blood sugar. Arrange a medical review for sudden onset, night sweats, unexplained weight change, fever, or sweating that began after a medicine change.

Ask whether the pattern suggests primary hyperhidrosis or a secondary cause, whether medicines or blood tests need review, and which treatment fits the affected areas. Ask about skin irritation, expected follow-up, and what to do if sweating occurs during sleep.