[Hypoglycemia--a dreaded complication of diabetes]

Hypoglycaemia is a common side effect of insulin therapy in type 1 diabetes. In patients with type 2 diabetes treated with blood-glucose lowering agents of the sulphonylurea group, hypoglycaemia is less frequent than in insulin-treated patients. In most patients strict metabolic control increases the risk of hypoglycaemia, but this risk may be reduced if patients are offered individualised insulin treatment in combination with active support and education. Previously experienced hypoglycaemic episodes and lack of endogenous insulin production are risk factors for repeated episodes. Patients with longstanding diabetes and loss of warning symptoms have increased risk of severe hypoglycaemic episodes, which may lead to loss of consciousness or convulsions. Driving performance is significantly disrupted at relatively mild hypoglycaemia, and persons with diabetes should not start driving when their blood glucose is in the 4-5 mmol/l range without prophylactic treatment. They ought to have carbohydrate-rich snacks easily available in the car and should stop driving if they feel hypoglycaemic. Repeated episodes of severe hypoglycaemia seem to be associated with cognitive dysfunction. When deciding the targets of blood-glucose lowering therapy, the risk of severe hypoglycaemia must be weighed against the beneficial effects of good metabolic control.