The shoulder, a very common site of pain syndromes in medical practice, lends itself well to precise clinical analysis and identification of the pain-sensitive structure or structures. Once identified, rational and effective management can be applied, associated with predictably good prognosis. Early identification of the emerging specific syndrome is important in decreasing the duration of the clinical disorder and in achieving optimum return of shoulder function. Laboratory and X-ray studies are not commonly required in diagnosis and management. There are a confusing variety of names attached to the many shoulder pain syndromes; however, there are two most common categories. One is associated with severe pain but little or no limitation of shoulder movement (at least passive movement), in which the pain-sensitive structure is tendon or tendon sheath; the other is associated with both pain and limitation of active and passive motion, in which the pain-sensitive structures are capsule, bursa, and synovium as well as muscle and multiple tendons.