Is there a difference between crps and chronic pain syndrome? if so what's the difference?

Not the same.: Complex regional pain syndrome (crps) is one of hundreds of causes of chronic pain. Crps has pain as the main symptom. However, there are many physical symptoms that help make that diagnosis. Chronic pain syndrome is generally used to describe physical and psychological changes due to chronic pain, which may can be pain from any number of causes, either known or unknown causes of pain.

Very different: Crps is a painful disorder coming from damaged, malfunctioning nerves that results in a symphony of nerve related pain and symptoms. Chronic pain syndrome is a combination of physical and behavioral changes that occurs in any patient that suffers from chronic pain of any kind. Crps patients frequently have a chronic pain syndrome whereas cps patients don't all have crps.