The thoracic outlet is situated within or is the area between the ribcage and the collarbone. It constitutes various anatomical structures which passes through this area and are very complicated in nature. It includes the esophagus, trachea, nerves, and blood vessels. Thoracic outlet syndrome causes severe pain in the region of neck, shoulder, chest, arm, and/or hand. The reason behind the pain is the compression of blood vessels and nerves which directly affects the thoracic region and causes pain and abnormal sensations.