What should you know about biochemical hyperthyroidism?

The thyroid helps regulate energy use, temperature and heart activity. Biochemical hyperthyroidism is a laboratory description, not a complete diagnosis. A clinician usually considers thyroid-stimulating hormone alongside thyroid hormone results, symptoms, examination findings and possible causes. People with hyperthyroidism commonly experience palpitations, excessive sweating, heat intolerance, feeling anxious, difficulty sleeping or diarrhoea, but symptoms differ between people. Supplements, prescribed medicines and recent illness can affect interpretation.

Arrange a clinical review and bring the test report, a list of medicines and supplements, and details of symptoms. Do not stop thyroid medicine or begin iodine products without advice. Your clinician may repeat thyroid blood tests, assess the neck and pulse, and decide whether specialist review or treatment is needed. Until reviewed, mention persistent racing heartbeat, tremor, unexplained weight change, heat sensitivity or sleep disruption.

Seek urgent help for chest pain, severe breathlessness, fainting, confusion, a very fast or irregular heartbeat, or a high fever with marked agitation or weakness. Symptoms can become more concerning during infection, after surgery or when thyroid medicines are changed. Emergency assessment is appropriate when severe symptoms appear, regardless of whether the blood-test result has already been explained.

Ask which thyroid results are abnormal, whether another test is needed, what cause is being considered, how symptoms should be monitored and when treatment or repeat testing should occur.