Currently there is no specific test that can confirm CRPS. Its diagnosis is based on a person’s medical history, and signs and symptoms that match the definition. Since other conditions can cause similar symptoms, careful examination is important.  As most people improve gradually over time, the diagnosis may be more difficult later in the course of the disorder.

Testing also may be used to help rule out other conditions, such as arthritis, Lyme disease, generalized muscle diseases, a clotted vein, or small fiber polyneuropathies, because these require different treatment.  The distinguishing feature of CRPS is that of an injury to the affected area.  Such individuals should be carefully assessed so that an alternative treatable disorder is not overlooked.

Magnetic resonance imaging or triple-phase bone scans may be requested to help confirm a diagnosis.  While CRPS is often associated with excess bone resorption, a process in which certain cells break down the bone and release calcium into the blood, this finding may be observed in other illnesses as well.