What should you know about hyperthyroidism untreated?

When thyroid hormone remains high, the body stays in an accelerated state. People may notice palpitations, excessive sweating, heat intolerance, feeling anxious, poor sleep, diarrhoea, weight change or muscle weakness. Ongoing overactivity can place extra demand on the heart and may contribute to an irregular rhythm. It can also affect bone strength and muscle function over time.

Risk is not determined by one symptom, and a symptom does not establish the diagnosis. A clinician uses thyroid blood tests and an assessment of the cause to decide how quickly treatment is needed.

Arrange a primary-care or endocrinology appointment if symptoms continue, recur, or interfere with sleep and normal activity. Bring your medicine and supplement list, describe when symptoms began, and mention pregnancy, heart disease or previous thyroid problems. Avoid self-treating with iodine or borrowed medicines. If treatment has already been prescribed, take it as directed and attend monitoring appointments even when you feel well.

Seek emergency care for chest pain, severe breathlessness, fainting, confusion, a very fast or irregular heartbeat, or a high temperature with severe agitation. Get same-day advice for repeated vomiting, severe diarrhoea, dehydration, rapidly worsening weakness or inability to take medication. These changes can signal a serious escalation of thyroid overactivity or another urgent illness.

Ask how your thyroid levels will be checked, what is causing the overactivity, which treatment is suitable, how heart or bone health will be considered, and which warning signs require immediate help.