It’s a small, butterfly-shaped gland at the base of your neck, but don’t let its small size fool you. The thyroid plays an important role in your health. Dr. Ruth Horowitz, Chief, GBMC’s Division of Endocrinology and Metabolism, talked with Mary Beth Marsden and Don Scott, about the top causes of thyroid disease and how an over- or underactive thyroid can affect everything from your heart rate to body temperature.