THE THYROID gland is an endocrine gland in the front of your neck, just below your Adam’s apple. It is made up of two lobes, each about the size of a plum cut in half.
The two lobes lie on either side of the wind-pipe.
It makes two hormones, thyroxine (T4) and triiodothyronine (T3) which are excreted into the blood. These hormones are required for all the cells in the body to work normally. In the cells and tissues of the body T4 is converted into T3. It is the T3 that is derived from T4 or excreted as T3 from the thyroid gland, which is biologically active and influences the activity of all the cells and tissues of the body.
What do thyroid hormones do?
The T3 which comes from the T4 and also that which is secreted directly by the thyroid gland influence the metabolism of body cells. It regulates the speed with which the body cells work.
What can go wrong?
• Hypothyroidism (underactive thyroid) – not enough thyroxine is produced for the bodies needs.
• Hyperthyroidism (overactive thyroid) – too much thyroxine is produced for the bodies needs.
Hypothyroidism is the most common.
Thyroid disorders tend mainly to occur in women, although they can occur in anybody, even children and babies.
Hypothyroidism: tiredness, feeling cold, slow heart rate, constipation, weight gain, poor concentration, depression.
Hyperthyroidism: weight loss, rapid heart rate, increased bowel movements or diarrhea, heat intolerance, anxiety and sometimes sore gritty eyes.
Sometimes there are very few symptoms. A simple blood test at your will confirm whether you have a thyroid disorder.
Other thyroid disorders
• Thyroid eye disease – this affects people with an overactive thyroid due to Graves’ disease
• Nodules or swelling – these lumps can stop the gland from working properly or may just be uncomfortable.
• Thyroid cancer – this is very rare but it is important to get a doctor to check any lumps in the neck
• Having a baby can sometimes trigger a thyroid disorder. This is known as post partum thyroiditis. It is usually a temporary but can return each time you have a baby.
How is the thyroid controlled?
In the brain there is a gland known as the pituitary gland. The pituitary gland senses the level of thyroid hormones in the blood and reacts by secreting a hormone called thyroid stimulating hormone (TSH) and this hormone activates the thyroid gland to produce more T4 and T3.
When the thyroid levels rise above normal the pituitary stops secreting TSH so that the thyroid stops working so hard and the production of T4 and T3 is reduced.
What causes thyroid disorders?
There are many different causes of thyroid disease but the most common cause is autoimmune thyroid disease – a self destructive process in which the body’s immune system attacks the thyroid cells as though they were foreign cells. In response the thyroid gland becomes either under or overactive. Thyroid disorders can run in families.
Thyroid disease is easily diagnosed by a simple blood test.
Most thyroid disorders are treated with medication. There are other treatments for conditions which cannot be treated with medication.
If you are concerned that you have any of the symptoms then contact the Family Medical Centre to arrange to have a blood test.