HealthInfo Canterbury

Goitre (enlarged thyroid gland)

A goitre is a swelling or enlargement of the thyroid gland. It doesn't necessarily mean a tumour or cancer. Goitre is more common in women, people older than 40 and those with a family history of goitre.

Your thyroid gland is found in the lower front of your neck. It produces thyroid hormones, which are carried in your blood through your body. Thyroid hormone is important because it helps your body use energy, stay warm and keep your brain, heart, muscles and other organs working as they should.

Causes of goitre

There are a number of factors that may cause a thyroid gland to enlarge. The common causes are:

• Iodine deficiency – Your body needs iodine to produce thyroid hormone. If you aren't eating enough iodine‑rich food, your thyroid gland can enlarge. This is uncommon in New Zealand where iodine is routinely added to table salt and other foods.
• Graves' disease or Hashimoto's disease – These are autoimmune diseases where the body's own immune system affects the thyroid gland. In Graves' disease it makes too much thyroid hormone and in Hashimoto's disease it doesn't make enough.
• Multinodular goitre – A few solid or fluid‑filled lumps called nodules develop in both sides of your thyroid gland.
• Thyroid cancer.

Symptoms of goitre

In most cases, the only symptom of goitre is the appearance that your neck is swelling. The size of the swelling may vary from a single small lump to a large swelling (mass) at the front of the neck. Sometimes an enlarged thyroid can place pressure on your oesophagus and windpipe. This can lead to symptoms such as:

• a tight feeling in your throat
• difficulty swallowing food, especially solid food
• a cough
• a change of voice or hoarseness
• difficulty breathing, especially when lying flat on your back
• pain in the area of your thyroid.

Depending on the cause of the goitre, some people may also have the symptoms of an overactive thyroid or underactive thyroid.

Diagnosing goitre

In most cases, your doctor might notice a swelling in your neck area during a routine examination. They may also perform other tests, including:

• blood tests
• an ultrasound of your thyroid
• a thyroid scan
• a biopsy (removal of sample tissue or cells).

Treating goitre

Treatment for goitre depends on the cause of your goitre, how large your thyroid has grown and your symptoms. If your goitre is small and isn't bothering you, you and your doctor may decide that it doesn't need to be treated. But the goitre will be closely watched for any changes.

The three main treatment options are medication, radioactive iodine treatment, and surgery.

Medications

The appropriate medication for you to treat your goitre depends on the cause. If the cause is:

• a lack of iodine, your doctor may prescribe small doses of iodine supplements
• an underactive thyroid (hypothyroidism), your doctor may prescribe levothyroxine which is identical to the thyroid hormone produced naturally by the body (this is called thyroid replacement therapy)
• an overactive thyroid (hyperthyroidism), then your doctor may prescribe medications such as carbimazole and propylthiouracil.

Radioactive iodine treatment

In some cases, if your goitre is caused by an overactive thyroid gland, your doctor may prescribe radioactive iodine which you take orally as a liquid or capsule. The aim is to shrink your thyroid gland. The iodine goes to your thyroid gland and kills thyroid cells, which shrinks the gland.

After radioactive iodine treatment, you may be prescribed thyroid hormone replacement therapy as ongoing treatment.

Surgery

You may need an operation to remove part or all of your thyroid. It's an option if:

• your goitre is large and causes problems with breathing and swallowing
• your goitre has nodules
• there is cancer.

Depending on the amount of thyroid gland removed, your doctor may prescribe thyroid hormone replacement therapy as ongoing treatment.

  HealthInfo recommends the following pages

• American Thyroid Association – Goitre

  Details about goitre, your thyroid gland, diagnosis and treatment.

• Patient.info – Goitre (thyroid swelling)

  Detailed information about goitre, including causes, symptoms and treatment.

Content shared between HealthInfo Canterbury, KidsHealth and Health Navigator NZ as part of a National Health Content Hub collaborative. Last reviewed May 2020.

Sources

Page reference: 81887

Review key: HITHY-49064