Hypoglycemia in infants and children.

Our understanding of the many different causes of hypoglycemia has vastly expanded in recent years. Most hypoglycemic disorders in infants and children are due to defects in the metabolic systems involved in fasting adaptation or the hormone control of these systems. As a result of these defects, infants and children have an abnormal adaptation to fasting, which results in hypoglycemia. The "critical sample" allows one to assess the integrity of the fasting systems when hypoglycemic. An understanding of the pathophysiology of these disorders establishes a foundation for a rational approach in evaluating the etiology of the hypoglycemia and developing the most appropriate management plan.