Diabetes mellitus and the nervous system

Diabetes mellitus is a disorder in which the concentration of blood glucose is persistently raised above the normal range. It occurs either because of a lack of insulin or because of the presence of factors which oppose the action of insulin. Hyperglycaemia results from insuYcient insulin action. There are many associated metabolic abnormalities-notably, the development of hyperketonaemia when there is a severe lack of insulin, together with alterations of fatty acids, lipids, and protein turnover. Diabetes is a permanent condition in all but a few special situations in which it can be transient.