A good way to understand the many causes of chronic pain is by considering phantom limb pain. When people lose an arm or leg in an accident or surgery, about half of them will still feel that the limb is there. About half of those people develop serious pain in the phantom limb. Obviously, this isn’t due to physical injury going on in the moment. It’s a misunderstanding by the brain of the signals it is getting and not getting. The brain figures the signals add up to something seriously wrong, so it sends out an urgent pain message.
The NIH National Institute of Diabetes and Digestive Diseases and Kidney Diseases says it, “currently supports studies that are working toward obtaining FDA licensure to reclassify islet allo-transplantation as therapeutic. In other countries, such as Canada and Scandinavia, islet allo-transplantation is no longer considered experimental and is an accepted therapy in certain patients.” It adds that “Some patient advocates and islet researchers feel that islet allo-transplantation is close to having a therapeutic label.”