What is my thyroid gland?

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

What is hyperthyroidism?

Hyperthyroidism (sometimes called thyrotoxicosis or overactive thyroid) is a condition where your thyroid gland is too active, and makes or releases too much thyroid hormone. The most common cause of hyperthyroidism in Australia is Graves’ disease. This is an autoimmune condition where your immune system stimulates your thyroid to produce too much hormone. Hyperthyroidism can also be caused by your thyroid becoming inflamed (thyroiditis) or by nodules (lumps) inside your thyroid that become overactive. Some people have underactive thyroids, this is called hypothyroidism.

What are the symptoms and signs of hyperthyroidism?

If you have an overactive thyroid, you may feel anxious or nervous, be unable to tolerate heat, have heart palpitations and feel tired. You may also lose weight, even if you’re eating the same amount of food.

Other symptoms and signs may include:

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

See your doctor if you have any of these symptoms.

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How is hyperthyroidism diagnosed?

Your doctor will check your neck to see if your thyroid is larger than normal or has nodules (lumps). They will also look for other signs of an overactive thyroid such as a fast heart rate.

To diagnose hyperthyroidism, your doctor may refer you for a blood test called a thyroid function test, to measure the level of your thyroid hormones. You may also need an imaging test called a thyroid scan.

When should I see my doctor?

See your doctor if you have any of the symptoms of hyperthyroidism. Many people live with an undiagnosed thyroid disorder. It can be difficult to diagnose, due to many symptoms being similar to those of other medical conditions.

Be sure to let your doctor know about your symptoms, your family history, and if any member of your family has previously had an autoimmune condition or thyroid disease.

How is hyperthyroidism treated?

If your doctor diagnoses an overactive thyroid, they may recommend one or more different treatments. Medicine can reduce the amount of hormone your thyroid produces. You may also need radioactive iodine therapy, which involves taking a drink or capsule that contains radioactive iodine, to shrink your thyroid.

If neither of these treatments is suitable, the thyroid or part of it could be removed by surgery (thyroidectomy). Speak with your doctor about the risks and benefits of this procedure, as surgery can sometimes cause damage to the glands and nerves around the thyroid.

Your doctor might also prescribe medicine to control your symptoms, such as medicine for a fast heart rate and palpitations. You might also need medicine for your eyes if they are affected by Graves’ disease.

Resources and support

The Australian Thyroid Foundation offers further information on definitions, causes, conditions and treatments, as well as questions to ask your doctor.