Thoracic outlet syndrome involves a group of disorders that lead to compression at the thoracic outlet. The thoracic outlet is the space between the clavicle (collarbone) and the first rib. Within this region are nerves and blood vessels that supply the shoulder and arm, such as the brachial plexus, subclavian artery, and subclavian vein.
Thoracic outlet syndrome often results in pain, numbness, and muscle weakness in the upper extremities. The type and severity of symptoms will depend on the cause of thoracic outlet syndrome and whether nerves, blood vessels, or both are compressed.
Fortunately, thoracic outlet syndrome can usually be treated with physical therapy and pain management. Rarely, surgical intervention may be required.