What happens if hyperthyroidism is not treated?

Hyperthyroidism means the thyroid releases more hormone than the body needs. Ongoing overactivity may cause heat intolerance, sweating, anxiety, tremor, palpitations, poor sleep and unintentional weight loss. Over time, the extra workload can strain the heart and contribute to an irregular heartbeat. It can also weaken bones and reduce muscle strength. Symptoms may fluctuate, but feeling better for a while does not show that the thyroid problem has settled.

A sudden severe worsening can cause a medical emergency, particularly with a very fast heartbeat, high temperature, marked agitation, confusion or collapse. The risk is higher during illness, after surgery or when prescribed treatment is stopped without medical advice.

Arrange a GP Consultation if you have persistent symptoms or have already been told that your thyroid is overactive. A Thyroid Function Test checks hormone patterns in the blood and helps guide the next step. Treatment may involve medicine, radioactive iodine or surgery, depending on the cause and your circumstances. Take prescribed medicine as directed and tell the clinician about heart symptoms, pregnancy, other medicines and supplements. Do not change a dose or stop treatment on your own.

Seek emergency help for chest pain, fainting, severe breathlessness, a very fast or irregular heartbeat, new confusion, collapse or a high temperature with intense agitation. Contact a clinician promptly if palpitations are recurring, weight is falling without trying, or symptoms such as heat intolerance and tremor are becoming harder to manage.

Ask what is causing the overactive thyroid, which tests are needed, how quickly treatment should begin, and how your heart rate and bone health will be monitored. Ask what symptoms should prompt urgent help and what to do if a dose is missed.