What should you know about sudden hyperthyroidism?

The thyroid makes hormones that influence heart rate, temperature control, digestion, energy, and the nervous system. Excess hormone may cause palpitations, tremor, sweating, heat intolerance, anxiety, difficulty sleeping, diarrhoea, or unplanned weight loss. Some people notice a swollen neck or eye changes, while others mainly feel restless or unusually tired.

These symptoms have many possible causes, so they do not confirm hyperthyroidism. A clinician can review your symptoms, pulse, medicines, supplements, and medical history, then request thyroid blood tests. Further tests may be needed to identify the cause.

Arrange a timely medical appointment, especially if symptoms are new, persistent, or worsening. Keep a note of your pulse, temperature-related symptoms, bowel changes, sleep, weight change, and any thyroid or iodine-containing products. Do not start thyroid medicine or supplements without advice.

Until assessed, reduce avoidable stimulants such as excess caffeine, stay hydrated if you have diarrhoea or sweating, and ask before taking medicines that can affect heart rate. Treatment depends on the cause and test results.

Seek emergency help for chest pain, fainting, severe breathlessness, confusion, a very fast or irregular heartbeat with weakness, or a high temperature with marked agitation or drowsiness. Severe vomiting or diarrhoea with dehydration also needs urgent assessment.

Which thyroid tests do I need? Could a medicine or supplement be contributing? Should I limit exercise or caffeine while this is being assessed? Which pulse, heart, or temperature symptoms require urgent help?