The thyroid is a small, butterfly-shaped gland located at the base of the neck just above the collarbone. It produces hormones that influences almost all of the metabolic processes in the body. The thyroid can produce too much hormone, called hyperthyroidism, or not enough, called hypothyroidism, which can lead to many different disorders. Four of the most common disorders of the thyroid are Hashimoto’s disease, Graves’ disease, goiter, and thyroid nodules.