Right now, there is no one specific test that can tell if you have CRPS so your doctor has to rely on a few things to make the diagnosis. First, your doctor will take a thorough history, including any reports of injuries or traumas, like fractures or surgeries. He or she will make note of any signs or symptoms of CRPS and may do some tests to rule out other disorders that may have similar signs and symptoms.
Your doctor may apply a pinprick, heat or cold to the area to see your reaction and if this causes pain. You may be sent for X-rays or a magnetic resonance image (MRI), which is a more advanced radiology examination. This will allow your doctor to have a look at the condition of the bone or bones in the affected area.
You could also be sent for a triple-phase or three-phase bone scan. Doctors aren't in agreement as to whether the test is helpful because statistics show that it may diagnose only half of people who have CRPS and even still, it is in the later stages of the disorder.
Other exams that test nerve and muscle function may be done but, as with the triple-phase bone scan, whether the tests are helpful is under debate.