Thyroid gland problems & disorders: Types, causes, diagnosis and treatment
What is the thyroid gland?
The thyroid is a butterfly-shaped gland that sits low on the front of the neck. It lies below your Adam’s apple, along the front of the windpipe. The thyroid has two side lobes, connected by a bridge (isthmus) in the middle. When the thyroid is its normal size, you’re unlikely to be able to feel it. It makes hormones to help regulate the body's metabolism and a person's growth
Types of thyroid problems
Problems and disorders associated with the thyroid gland include:
Causes of hyperthyroidism
All types of hyperthyroidism are due to overproduction of thyroid hormones, but the condition can be caused in several ways:
- Graves' disease. This is an auto-immune condition and is the commonest cause of an overactive thyroid gland.
- Toxic adenomas. Nodules develop in the thyroid gland and begin to secrete thyroid hormones, upsetting the body's chemical balance. Some goitres may contain several of these nodules.
- Subacute thyroiditis. This is where inflammation of the thyroid causes the gland to ‘leak’ excess hormones, resulting in temporary hyperthyroidism. The condition generally lasts a few weeks, but it may persist for months.
- Pituitary gland malfunctions or cancerous growths in the thyroid gland. In rare cases, hyperthyroidism can also be due to these causes.
Causes of hypothyroidism
Hypothyroidism, by contrast, stems from an underproduction of thyroid hormones. Since your body's energy systems require certain amounts of thyroid hormones, a drop in hormone production leads to lower energy levels. Causes of hypothyroidism include:
- Hashimoto's disease. In this autoimmune disorde r, the body’s own immune system attacks thyroid tissue, leading to reduced thyroid hormone.
- Removal of the thyroid gland. The thyroid may be surgically removed or chemically destroyed as a treatment for hyperthyroidism.
- Exposure to excessive amounts of iodide. Cold and sinus medicines, the heart medicine amiodarone or certain contrast dyes given before X-rays may expose you to too much iodine. You may then be at greater risk of developing hypothyroidism, especially if you have had thyroid problem s in the past.
- Lithium. This drug has also been linked to hypothyroidism.
Left untreated for long periods, hypothyroidism can bring on a myxoedema coma, a rare but potentially fatal condition that requires immediate hormone injections.