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 shoulder, to the outside of the arm, elbow joints, the forearm, and all the way up to the hand, and at the same time will be accompanied by the fingers of the numbness; 2, frozen shoulder: the pain characteristics are mainly in the peripheral part of the shoulder joint, including the deltoid muscle, the outer side of the upper arm, the inner part of the upper arm, and armpit and other parts of the shoulder, frozen shoulder pain is not generally more than the elbow joint.