Complex regional pain syndrome is a condition that often affects people after trauma or orthopedic surgery. An insult to the nerves or tissues can set off an inflammatory response that goes overboard. The nervous system seems to take off and doesn't slow down. Pain, hypersensitivity, and even bone loss can develop.
Your physician is right about testing. So far, there's no single diagnostic lab test, X-ray, or other imaging test that identifies this problem quickly and easily. X-rays don't show changes until late in the progression.
Bone scans do show increased blood flow to the affected area. But the test is only specific and sensitive enough in the early weeks of symptom development. And most doctors don't routinely suggest this test until many weeks of unresolved symptoms have gone by.
Most of the time, we have to rely on the history (what happened) and clinical signs and symptoms. If a patient doesn't get better in the expected timeframe, as red flag is raised in the mind of the doctor. Close follow-up is necessary to see changes occurring that point to CRPS.
Early detection and treatment are important in CRPS in order to avoid chronic problems. Unfortunately, this condition is often very difficult to diagnose. if your doctor thinks you may have CRPS, don't delay getting appropriate treatment.