The thyroid gland is located in the lower part of the neck, attached to the windpipe. It consists of right and left lobes, joined by a bridge of tissue (called the isthmus). A number of important structures lie close to the thyroid gland. The nerve which controls the voice box (larynx), called the recurrent laryngeal nerve, runs behind the thyroid gland. In addition, there are four glands called parathyroids that sit behind the thyroid. These glands are each about the size of a lentil and control the level of calcium in the blood.
The thyroid gland controls how fast the body’s metabolism runs (metabolic rate). It does this by producing two hormones (known as T3 and T4 (thyroxine)). Patients who have had all of their thyroid gland removed need to take thyroxine tablets for the rest of their life to replace these hormones.
The following sections describe problems with the thyroid that may require surgical treatment, and what this entails.