Patients with shoulder pain are most often diagnosed with bursitis or tendinitis of the rotator cuff. Also known as impingement syndrome, bursitis is an inflammation of the bursa that lies between the top of the humerus (arm bone) and the top of the shoulder. Normally, the rotator cuff tendons slide smoothly within this space. In some people however, the space becomes too narrow and the tendons and bursa become inflamed and thickened, which reduces the space even further.
Impingement syndrome or bursitis is characterized by shoulder pain that occurs when reaching overhead or sideways. There also may be pain when sleeping at night.
Approximately 90 percent of patients with shoulder pain will respond to non-operative treatments like rest, exercise and anti-inflammatory medication. Impingement syndrome or bursitis is often successfully treated by a prescribed physical therapy program, medication and sometimes a steroidal injection.