Thoracic Outlet Syndrome

TOS is a group of disorders caused by compression of the brachial plexus, subclavian artery, or vein at the thoracic outlet. Clinical features include upper extremity pain, numbness, weakness, and vascular compromise. Etiology includes anatomical variations, trauma, and repetitive activity. Diagnosis relies on clinical examination, imaging, and electrophysiological studies. Management includes physical therapy, postural correction, pharmacologic therapy, and surgical decompression; prognosis depends on severity and timely intervention.