A goitre is a swelling or enlargement of the thyroid gland. It does not necessarily mean a tumour or cancer. Goitre tends to be more common in women and in people over 40 years of age or those with a family history of goitre.
What is the thyroid gland?
The thyroid gland is found in the lower front of the neck. It produces thyroid hormones, which are secreted into the blood and then carried throughout the body. Thyroid hormone is important because it helps the body use energy, stay warm and keep the brain, heart, muscles and other organs working as they should.
What causes goitre?
There are a number of factors that may cause a thyroid gland to enlarge. The common causes are:
|Iodine deficiency||Iodine is needed for the body to produce thyroid hormone. A lack of iodine in your diet can sometimes cause your thyroid gland to enlarge Iodine deficiency is uncommon in New Zealand where iodine is routinely added to table salt and other foods.|
|Graves' disease||Graves disease is an autoimmune disease in which the body's own immune system affects the thyroid gland causing it to produce too much thyroid hormone. This may result in an enlarged thyroid gland.|
|Hashimoto's disease||Hashimoto's disease is an autoimmune disease in which the body's own immune system attacks the thyroid gland causing it to make less thyroid hormone.|
|Multinodular goitre||In this condition, a few solid or fluid-filled lumps called nodules develop in both sides of your thyroid gland, resulting in overall enlargement of the gland. Read more about thyroid nodules.|
|Thyroid cancer||Cancer of the thyroid can cause enlargement in the thyroid gland.|
What are the symptoms of goitre?
In most cases, the only symptom of goitre is the appearance of a swelling in the neck. 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 the gut (oesophagus) and windpipe (trachea). This can lead to symptoms such as:
- a tight feeling in the throat
- difficulty swallowing food, especially solid food
- change of voice or hoarseness
- difficulty breathing especially when lying flat on the back
- pain in the area of the thyroid.
How is goitre diagnosed?
In most cases, a goitre is discovered during a routine examination, when your doctor might notice the swelling in your neck area.
In addition, your doctor may perform other tests to confirm the diagnosis, such as:
To assess the functioning of your thyroid gland, your doctor will request a blood test called a thyroid function test. This test measures the levels of various thyroid hormones.
Your doctor may also request an antibody test that looks for certain antibodies that are produced in some forms of goitre. An antibody is a protein made by white blood cells. Antibodies help defend against invaders (for example, viruses) that cause disease or infection in the body.
Ultrasound of the thyroid
This test can help your doctor decide if the thyroid nodule is filled with fluid or thyroid tissue, and it can also measure the size of the nodule. The ultrasound is a painless test.
A thyroid scan
During this test, an isotope of radioactive iodine is injected into a vein in your arm. You then lie on a table while a special camera produces an image of your thyroid on a computer screen.
A biopsy is the removal of a sample of tissue or cells to be studied in a laboratory. A biopsy may be needed if there are large nodules in the thyroid gland. A biopsy is taken to rule out cancer.
How is goitre treated?
Treatment for goitre depends on the cause of the goitre, how large the thyroid has grown, and the symptoms your are experiencing. Treatment options include:
|No treatment (also called watchful waiting)||
|Radioactive iodine treatment||
The following links provide further information on goitre. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.
- Management of thyroid dysfunction in adults BPAC, NZ, December 2010