Diabetes mellitus can usually be reasonably well controlled on a
day-to-day basis with modern drug regimens. Nonetheless, the
risks of metabolic decompensation and iatrogenic hypoglycaemia
remain close at hand. Life threatening hyperglycaemia – with or
without ketosis – may be precipitated by intercurrent illness or
interruption of antidiabetic therapy; new cases of diabetes
frequently present as hyperglycaemic emergencies. Clinical outcomes
for patients with diabetes after myocardial infarction or
surgery may be compromised by sub-optimal metabolic control,
the presence of chronic co-morbidity in the form of microvascular
complications or atherosclerosis magnifying these risks. Pregnancy
continues to present particular hazards for mother and fetus.