[Current diagnostic criteria, current classification of and clinical approach to diabetes mellitus]

The new diagnostic criteria and new classes of diabetes mellitus have caused a certain amount of confusion. This work reviews and analyses the practical aspects of this chronic condition. The oral glucose tolerance test has specific indications which should be kept in mind. Type I and type II diabetes mellitus remain the two principal groups of classification, but individualisation of subtypes la and lb allows a better understanding of the pathogenesis of the disease. The third syndrome or type III is mainly found in tropical and subtropical areas. Its pathogenesis, toxic or malnutritive, is still unclear.