Severe hyperthyroidism symptoms: what to recognise

Hyperthyroidism means the thyroid releases more hormone than the body needs. This can speed up heart rate, bowel activity, and energy use. People may notice palpitations, excessive sweating, heat intolerance, feeling anxious, restlessness, reduced sleep, diarrhoea, muscle weakness, or unplanned weight loss despite eating normally. Night sweats may also occur. Some people develop eye discomfort or swelling, depending on the cause.

These symptoms can have other explanations, so they do not confirm hyperthyroidism alone. A clinician may assess your pulse, neck, eyes, medicines, and general health, then use thyroid blood tests to guide next steps.

Arrange prompt medical review if several symptoms appear together, especially palpitations, tremor, heat intolerance, or unexplained weight change. Keep taking prescribed treatment as directed and avoid starting thyroid supplements or high-stimulant products without advice. Note your symptoms, pulse if you have been shown how to check it, and any medicines or supplements.

Seek emergency care for chest pain, severe breathlessness, fainting, severe agitation or confusion, a very fast or irregular heartbeat, or extreme fever with worsening illness. These may indicate a serious complication requiring immediate treatment.

Ask which thyroid tests are needed, whether another condition or medicine could explain the symptoms, how to manage palpitations safely, and when your treatment should be reviewed.