CRPS, or complex regional pain syndrome, is diagnosed when other possible causes have been ruled out. CRPS is not a new illness; it was first identified in the Civil War among injured soldiers.
If your doctor suspects CRPS, it may be based on any or all of these tests:
Medical history: has there been any earlier injury or trauma?
Physical exam: often the color and temperature of the skin on the affected side differs from the other side.
X-rays: to be sure that nothing is broken or out of place
Bone scan: after injecting dye, the doctor can see the bones
Tests of the nervous system: to rule out other illnesses
Magnetic resonance imaging (MRI): to show body parts that cannot be seen on x-ray.