General health

What is thyroid disease?

Thyroid disease is a common condition affecting both men and women. The thyroid is a gland that lies over the windpipe at the front of the neck.

The thyroid gland produces two hormones called tri-iodothyronine (T3) and thyroxine (T4) that are involved in regulating our metabolism. Because thyroid hormones control these functions, an underactive thyroid can cause a general slowing down of bodily functions and this is called hypothyroidism. So along with tiredness, you might notice weight gain, constipation, low mood, loss of libido and even slowing down mentally. People can become aware of their hair thinning, skin becoming dry and even a deeper voice. It can be a cause of period disturbances and infertility in women, as well as general body aches and pains.

Some combination of these symptoms would usually prompt a visit to the GP and a standard blood test can be used to assess thyroid function – the results are conclusive in most cases but sometimes the test needs repeating. Upon receipt of your test results, your doctor will advise on suitable treatment or prescription medication as needed. For hypothyroidism, treatment aims to top-up or replace the thyroid hormone to a normal level, usually using levothyroxine tablets (a synthetic form of the natural T4 hormone).

The other main thyroid disease is an overactive thyroid (hyperthyroidism) and this often leads to weight loss and feeling hot all the time. If this is diagnosed, treatment can include a medicine that blocks the thyroid from producing hormones.

Another type of thyroid disease is an enlarged thyroid gland, known as a goitre. This is seen as a swelling at the front of the neck, and is usually caused by an iodine deficiency, but can also be linked to hypothyroidism or hyperthyroidism.

You can find more information about these conditions on the NHS website (, or the British Thyroid Foundation website (

Dr. Phelan By Dr. Phelan General Practitioner Published 12/07/2019