The thyroid gland is an endocrine gland located in the neck. It produces hormones that regulate many processes in the human body. It is located at the very front of the neck, and it’s shape resembles a butterfly; it has two lobes that are connected by a thin band of tissue known as the thyroid isthmus. Thyroid hormones are essential to maintain the proper function of many processes in the body. The thyroid gland produces thyroid hormones: T4 (thyroxine), T3 (triiodothyronine), and calcitonin. The gland releases these hormones into the blood, which transports them to all organs and tissues. If the thyroid gland produces too little thyroid hormone, the hypothalamus and the pituitary gland feedback to the gland to ensure that it starts producing more thyroid hormone. And conversely, if there is too much thyroid hormone in the blood, the hypothalamus and the pituitary gland ensure that the thyroid gland produces less thyroid hormone. The hypothalamus and the pituitary gland are both parts of the brain that regulate the amount of thyroid hormone in the blood through the secretion of other hormones. Thyroid hormones regulate practically all processes in the human body; as a result, thyroid disorders can cause a wide spectrum of symptoms.