Definition : A major life threatening metabolic condition occurring in diabetic patients leading to hyperglycaemia , ketoacidosis , dehydration and ketonuria . Pathophysiology: The lack of insulin primarily leads to hyperglycaemia and ketonaemia: Insulin insufficiency leads to reduced uptake of glucose into cells and increased blood concentration of glucose. As glucose are not taken into cells, alternative sources of energy are used. Most cells break down fatty acids instead of glucose which forms ketones. Ketone levels therefore reflects the glucose deficit in cells. Lack of insulin also leads to an increase in opposing hormones which lead to increased glycogenolysis, gluconeogenesis and lipolysis.