print   Print full article

The Thyroid

The thyroid is a small, butterfly-shaped gland just below the Adam's apple. This gland plays a very important role in controlling your body's metabolism, that is, how your body functions. It does this by producing thyroid hormones (thyroxine, or T4, and triiodothyronine, or T3), chemicals that travel through your blood to every part of your body. Thyroid hormones affect almost all tissues in the body and regulate many aspects of metabolism.

If you have enough thyroid hormone in your blood there is a feedback mechanism and the gland stops making the hormones. When the body needs more thyroid hormones, the gland starts producing again.

The pituitary gland, located at the base of the brain, tells the thyroid when to start and stop. The pituitary sends thyroid-stimulating hormone (TSH) to the thyroid and this hormone increases the production of thyroid hormones by the thyroid gland.


Last Review Date: April 1, 2017