The thyroid gland, a part of the endocrine (hormone) system, plays a major role in regulating the body's metabolism.
Review Date 6/14/2018
Updated by: Brent Wisse, MD, board certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.