Shoulder pain may occur on one or both sides of the shoulder, and is mainly associated with the shoulder joint itself, or its attached tendons and muscles, as well as the shoulder blade. The pain may refer to the upper and back part of the thorax, upper arm or even the entire arm.
According to TCM theory, shoulder pain may be caused by a disturbance of one of the six Yang channels of the hand or of the Lung channel.
Both External invasion and disorder of the Internal Zang-Fu organs may cause disturbances in one or more of these channels, leading to stagnation of Qi and Blood, at which point pain occurs.
More specifically shoulder pain is generally caused by invasion of External pathogenic factors, stagnation of Qi, stagnation of Blood or accumulation of Damp-Phlegm in the channels.
Shoulder pain may be attributed to any of the following disorders in Western medicine: subacromial bursitis, synovitis of the shoulder joint, periarthritis of the shoulder joint, tendinitis of the shoulder, calcification of the shoulder tendon, shoulder–hand syndrome, tendinitis of the supraspinatus muscle, calcification of the supraspinatus tendon, rheumatic arthritis of the shoulder and traumatic arthritis of the shoulder.