Hi, this could be due to thoracic outlet syndrome, cervical spondylosis, carpal tunnel syndrome etc. Symptoms due to thoracic outlet syndrome include
neck,
shoulder,
and arm
pain,
numbness, or impaired circulation to the extremities (causing discoloration). Often symptoms are reproduced when the arm is positioned above the shoulder or extended. Patients can have a wide spectrum of symptoms from mild and intermittent, to severe and constant.