Chronic Regional Pain Syndrome (CRPS), sometimes known as Reflex Sympathetic Dystrophy (RSD) is an abnormal, chronic, long-lasting pain that develops in a region that has been previously injured. More simply, CRPS could be defined as unexplained pain that simply will not go away under normal means.
The two types of CRPS – Type 1 and Type 2, are very similar. The difference being Type 1 is categorized as the issue arising from an injury to tissue in the extremities, while Type 2 sees the issue arise following a specific nerve injury.
Depending on the Type of CRPS that has developed, the pain may be severe and difficult to handle – and may spread to nearby areas of the body. The exact cause of CRPS is not clear – though it acts similarly to an overreaction to an injury in the same way we react to an allergy.