In 1981, Dr. AJ Tamoush gave the McGill Pain Questionaire to patients attending pain clinics. He found that the pain rating index among patients was 42. The higher the rating the more intense the pain. Yes, RSD pain is more severe and unrelenting than these and more than most chronic pain conditions.
RSD pain is always unpredictable and can vary from moment to moment.
In the early phases and in milder cases, most intense pain is limited within the general territory of the initial injury, while in severe cases, the pain, while most intense in the original area, becomes diffuse and poorly localized. Often symptoms will be seen in the distal portion on the affected extremity. If the right shoulder sustains the original injury, the right hand will develop, RSD symptoms even though it was never injured. Unless the pain disappeared spontaneously or is relieved with treatment, in time, it will usually spread to the quarter of the body, to other parts of the body or to the contralateral limb. Studies by Dr. John Bonica were used to develop this information.