My sister was diagnosed with CRPS not too long ago. I don’t see anything wrong with her arm but she says it’s a horrible burning pain. When I tried to look it up on the Internet, I saw that it was called something else and that everyone seems to have it differently. Is there really such a disease?

Complex regional pain syndrome, called CRPS for short, is a very real, very painful disorder that affects people after a seemingly minor injury sometimes. The problem is that CRPS is not understood and doctors don’t know what causes it or why it happens. They can’t even tell who would be at higher risk of developing it than others. Not only that, the symptoms and how the affect people can vary considerably from person to person.

As a result of so much that isn’t known, there is a good bit of confusion around the disorder, which used to be called reflex sympathetic dystrophy. In fact, it used to be thought that it was a mental disorder more than a physical one. Over the centuries, researchers tried to pin different causes, usually psychological, to CRPS because they couldn’t find any other way to explain it. Of course, as psychological thinking changed over time, so did the theories – but nothing really stuck and there still is no proof that CRPS is associated with a mental or psychological problem.