摘要：Progress in medicine and the resulting avalanche of medical literature in the past twenty five years have pointed up the inadequacies in the existing medical classifications. All required major changes, realignments, expansions, and revisions, not only to provide for the new material but also for much of the older material which, because of changing concepts, no longer fitted in the areas to which it had been assigned earlier. As a result most medical classifications in use have been revised or are in the process of being revised.
