The thyroid is a small, butterfly-shaped gland in the throat that releases hormones which regulate the body’s heart rate, temperatures, and metabolism. It is common for tumors to develop in or on this gland, but most are not cancerous. Even if non-cancerous, thyroid tumors can result in an overactive or underactive thyroid. Overactive thyroid hormone production, known as hyperthyroidism, is a common condition that causes an increase in metabolic function throughout the body. When a thyroid is underactive, the body does not produce sufficient hormones to keep the body at a normal metabolic rate. Proper thyroid function is essential to good health. Treatments for thyroid disorder can include a thyroidectomy, which is the surgical removal of the gland.