How diabetes was defined
It has been said that many questions in science are more easily understood by their history than by their logic, and the definition of diabetes is a good example of this. A raised blood glucose is the hallmark of diabetes, and a raised blood glucose defines diabetes. There have been may attempts to escape from this circular definition, the most successful being to define hyperglycaemia in epidemiological terms according to its consequences: i.e. by the degree of its association with vascular consequences deemed to be diabetic - thus creating another another circular definition. This article traces the road leading to our current, and still somewhat unsatisfactory, way of categorizing the hyperglycaemic disorders.