What are the symptoms of thoracic outlet syndrome?

Pain, numbness: Thoracic outlet syndrome can affect the vein, artery or nerves of the arms. Symptoms can include swelling of the arms, (vein compression) pain or numbness when using the arms overhead, or pain that can extend from the neck or shoulder down to the hands or fingers. Most symptoms are aggravated by doing things that narrow the space where vein, atery and nerve travelling to the arm are.