There is no diagnostic test or scan that can provide any definitive proof that you have, or don’t have, CRPS.  Tests can only rule out other conditions. A CRPS diagnosis is based on what your diagnosing doctor or specialist can actually see evidence of on the day that you are being diagnosed, based on physical examinations and by taking a medical history, including what symptoms you report having.

Some patients will display all of the signs and symptoms in one visit and will be easily and quickly diagnosed, some patients may come in to an appointment with few visible signs but develop more after a stressful conversation or examination and others may not.  For the diagnosis to be confirmed the clinician has to see the evidence of the signs for themselves on the day you are examined.

 The signs that you display can change from day to day with CRPS, so it could take more than one visit to be properly diagnosed.  For those who generally have all the symptoms of CRPS, but are not diagnosed in one visit, repeat visits to confirm or deny the diagnosis are advised as an early diagnosis is required for the best possible outcome.


The diagnosis is based on the ‘Budapest Criteria’ which was developed in 2003


Complex Regional Pain Syndrome is broken into 3 different types.

Type I:    – where there is no major nerve damage.

Type II:  – where there is major identifiable nerve damage

Type III:  – NOS – Not Otherwise Specified – partially meets diagnostic criteria, no other diagnosis better fits the   symptoms. (This category includes those patients who have fewer signs and symptoms than are required to fulfil the Budapest Criteria; including those who had more documented signs and symptoms in the past, if their current signs and symptoms are still felt to be best explained by a CRPS diagnosis)

Picture of the Budapest Criteria


Downloadable Budapest Criteria


Continuing pain which is disproportionate

CRPS is usually precipitated by a trauma, such as an accident, a fracture or a surgery, or following a medical emergency such as a heart attack or a stroke, but CRPS can also occur after a very trivial incident and, on occasion, can develop spontaneously. How large or small the trauma or inciting event was makes no difference to the severity of CRPS.  The onset of CRPS symptoms usually appear within one month of the inciting event or immobilisation of the limb.   The pain that you are feeling is much higher than you would be expecting to feel after the trauma or accident.

Sensory as a symptom

For this category you must report feeling increased pain to normally painful stimuli – such as a pin prick or allodynia, which is a painful response to non-painful stimuli; such as bed sheets causing pain, light touch being painful, warm water or a light breeze blowing on the affected area hurting.  You might also find movement or pressure painful.

 Vasomotor as a symptom

 You need to report whether you find the affected is hot or cold to touch or if the skin colour is abnormal.

Sudomotor as a symptom

In this category you would report if you had any unusual sweating or swelling of the area.


Motor changes can include the way that the area generally functions.  You would report any general weakness, unusual sensations, tremors, unusual limb or hand/foot positions etc.  Trophic changes include thinning of the skin, excess or loss of hair growth, fast, slow or ridged nail growth etc.

Sensory as a sign

The clinician must observe evidence of increased pain to normal stimuli (pinprick) or to allodynia, somatic pressure or joint movement.  Some people may feel increased pain to light pressure, for others it will be deep pressure.  The clinician will want to touch you in some fashion to establish the evidence for this category.  They should ask first and will let you know what they are about to do to decrease your stress.

Vasomotor as a sign

The clinician will usually use an infrared thermometer to test the temperature of your affected area and compare it to the opposing limb.  A difference of greater than 1 degree Celsius is considered a positive result. They will also look for evidence of any visible skin colour changes.

Sudomotor as a sign

The clinician needs to check for evidence of sweating by sight or touch or signs of any visible swelling.

Motor/Trophic as a sign

The clinician is able to check for ease or quality of movement by checking the range of motion of the joint and by checking resistance & strength testing if pressure can be tolerated on the affected limb or body part.  They will also check for evidence of trophic chances, such as abnormal growth of hair, thin or shiny skin or abnormal nail growth by comparison to a non-affected body part.

There is no other diagnosis that better fits

 If there is any other disease or injury that can explain the signs and symptoms, then a diagnosis of CRPS is not indicated.

“If hell were a medical condition it might look something like Complex Regional Pain Syndrome’

Tom Haederle, of John Hopkins University, while trying to provide an analogy for the pain of CRPS*


1 Harden R. et al., Complex Regional Pain Syndrome: Practical diagnostic and Treatment guidelines, 4th edition, Pain Medicine 2013; 14:180 – 229