Upper arm pain may be due to a variety of reasons, the most common is the nerve root compression caused by cervical disc herniation, or frozen shoulder, the details are as follows: 1, nerve root compression: when the cervical disc compression to the left side of the nerve root, it will cause the left side of the upper arm of the radiating pain, the scope of the pain and the area mainly including the neck to the outside of the shoulder to the upper arm, the elbow joint, the forearm, all the way to the hand, and at the same time, it will also be accompanied by the fingers of the numbness; 2, frozen shoulder: the pain is characterized by the main in the shoulder joint of the peripheral areas, including the deltoid muscle, the outer side of the upper arm, the upper arm medial side, and the axilla and other parts of the pain caused by the frozen shoulder is generally not more than the elbow joint.