A number of conditions can cause shoulder pain. Diagnosis of shoulder pain begins with a history and a physical examination to discover:
The location and nature of the pain and swelling
If there is any limitations of movement
Special diagnostic tests can then define the exact nature of the problem.
X-rays can show arthritis, a dislocation, and other problems with the bones of the shoulder.
Magnetic resonance imaging (MRI) uses strong magnetic fields and radio waves to create a series of cross-sectional images of the joint. These images can provide a detailed map of the injury, particularly one affecting the soft tissues of the joint.
Arthrography is a technique in which a harmless dye is injected into the shoulder, and then x-ray images are taken. It can identify problems, particularly rotator cuff tears, as the dye passes through the tear. The dye is absorbed safely into the body. It's not as widely used anymore since MRI can clearly show a rotator cuff tear. But an MRI may be enhanced using this technique, so it is still used in selected situations.