Thyroid gland is one of the endocrine organs present in front of the neck. It is a butterfly shaped organ and has two side lobes, connected by a bridge (isthmus) in the middle.The thyroid secretes hormones namely Triiodothyronine (T3) and Thyroxine (T4) and it is controlled by the pituitary gland which secretes the thyroid stimulating hormone and which in turn stimulates the thyroid gland. Thyroid hormones act throughout the body, influencing metabolism, growth & development, and body temperature.