Why does hyperthyroidism cause excessive sweating?

Thyroid hormones influence how quickly many body systems work. When thyroid hormone is too high, the body may generate more internal heat and respond strongly to warmth, activity, or stress. Sweat glands then release more moisture to cool the skin. You may also notice warmth, a fast or irregular heartbeat, shakiness, restlessness, difficulty sleeping, or unplanned weight loss.

Sweating is not specific to thyroid disease. Hot weather, exercise, anxiety, infection, medicines, and other health conditions can produce the same symptom. A clinician usually considers the full pattern and may arrange thyroid blood tests.

Keep cool with breathable clothing, fluids, and a comfortable room temperature. Note when sweating occurs and whether it comes with palpitations, tremor, diarrhoea, sleep changes, or heat intolerance. Do not change thyroid medicine without medical guidance. If hyperthyroidism is confirmed, treatment may involve medicine, radioiodine, or surgery depending on the cause and your health.

Book an assessment for persistent unexplained sweating, especially with a racing heartbeat, tremor, heat intolerance, or weight change. Seek urgent help for severe chest pain, fainting, marked breathlessness, confusion, or a very fast heartbeat with feeling acutely unwell.

Ask whether your symptoms warrant thyroid testing, what may be causing hormone excess, and which treatment is suitable. Discuss how to manage sweating safely, whether any current medicine affects your symptoms, and which heartbeat or temperature symptoms should prompt urgent review.