What is the thyroid?

The thyroid is a gland in the neck, near the base of the throat. The thyroid gland makes hormones that help control some of the body’s metabolic processes, such as heart rate, blood pressure, body temperature and weight.

What is hyperthyroidism?

Hyperthyroidism (sometimes called thyrotoxicosis) occurs when the thyroid gland is overactive. The most common cause of hyperthyroidism in Australia is Graves’ disease, an autoimmune condition where the immune system stimulates the thyroid to produce too much hormone. Hyperthyroidism can also be caused by the thyroid becoming inflamed (thyroiditis) or by nodules (lumps) inside the thyroid that become hyperactive.

What are the symptoms and signs of hyperthyroidism?

The most common symptoms of hyperthyroidism are feeling anxious or nervous, being unable to tolerate heat, having heart palpitations, feeling tired and losing weight, even if you’re eating the same amount of food.

Other symptoms and signs can include:

• an enlarged thyroid (goitre)
• breathlessness
• eye problems
• increased appetite
• tremor
• sweating
• changes in bowel habits or menstrual patterns
• thin skin
• fine, brittle hair
• difficulty sleeping

See your doctor if you have any of these symptoms.

How is hyperthyroidism diagnosed?

Your doctor will check your neck to see if your thyroid is enlarged or has nodules (lumps), and will look for other signs of hyperthyroidism such as a fast heart rate.

To diagnose hyperthyroidism, a blood test is done to measure the level of your thyroid hormones. An imaging test called a thyroid scan may also be done.

How is hyperthyroidism treated?

If you are diagnosed with hyperthyroidism, a few different treatments can be given. Medicine can reduce the amount of hormone your thyroid produces, or you could be given radioactive iodine therapy, which involves taking a drink or capsule that contains radioactive iodine, to shrink the thyroid.

If neither of these treatments is suitable, the thyroid or part of it could be removed by surgery although this carries a risk of damaging surrounding glands and nerves.

You could also be prescribed medicine to control a fast heart rate and palpitations, or medicine for your eyes if these are affected by Graves’ disease.