Complex Regional Pain Syndrome (CRPS) refers to a set of symptoms with no identified cause, typically affecting an arm, hand, leg, or foot.

Symptoms include pain that may feel aching or electric-like, along with sensations such as tingling, burning, or numbness.

It often begins after an injury, though the injury may not involve the affected area. Swelling or changes in skin color (red, blue, or purple) may also occur.

CRPS can be limited to one limb or spread to others.

There is no evidence that a structural disease causes CRPS, and symptoms have been successfully treated using the mindbody approach. This suggests that CRPS is likely caused by the brain, with possible involvement of the autonomic nervous system in cases with swelling or skin color changes.

If medical evaluations do not identify any disease or injury, or if treatments fail to provide expected improvement, it is likely that the brain plays a role in generating or contributing to the pain or illness. This is called a neuroplastic symptom.