Often we don’t know why some people develop thyroid nodules and others don’t, but it is more common in women, in people with a family history of nodules, and also with increasing age.
Benign (non-cancerous) nodules initially develop due to local changes in thyroid tissue which makes some cells more sensitive to growth signals and causes them to grow faster. These eventually develop into nodules which can sometimes be felt and cause local symptoms.
Inflammation within the gland and more rarely radiation treatment to the neck or head area can also predispose to nodule formation. Individuals that lack iodine in their diet (or regions in the world that lack iodine) are also prone to enlarged thyroid glands as more thyroid tissue is required to allow the gland to absorb sufficient iodine from the blood in order to produce adequate thyroid hormone. There are many foods that contain iodine including seafood, dairy products and eggs.
