How Your Thyroid Works

The thyroid gland produces hormones that control metabolism. The thyroid hormones are called T3 and T4, which are produced by the follicular cells of the thyroid gland. These hormones help regulate the body’s growth and development, as well as its energy levels.

Your thyroid gland is located in your neck just below your Adam’s apple (larynx). It’s about the size of a walnut, with two lobes on either side of your windpipe (trachea).
The Different Types of Thyroid Disease

There are several types of thyroid disease, each with its own symptoms and causes. The most common forms include:

Hashimoto’s disease, which is an autoimmune disorder that occurs when your immune system attacks the thyroid gland. It can cause hypothyroidism (underactive thyroid) or hyperthyroidism (overactive).
Graves’ disease, another autoimmune disorder in which antibodies produced by your body trigger an inflammatory response that leads to hyperthyrotropinemia–an overproduction of T3 and T4 hormones.
Thyroid cancer (papillary carcinoma), which accounts for up to 80 percent of all cancers affecting this organ; it typically occurs in women between ages 30-50 but also affects men during their 60s or 70s if they’ve been exposed to radiation earlier in life as part of medical treatment such as radiation therapy after having undergone surgery for cancer elsewhere on the body