Hypoglycemia in the newborn is a common and potentially serious problem. Glucose is the key substrate for the brain, and significant or persistent hypoglycemia can result in permanent impairment in brain growth and development. At delivery there is an abrupt interruption of placental glucose transport, causing a decrease in the newborn’s glucose level in the first 4 to 6 hours. Healthy newborns rebound well because they have enhanced glycogen stores that are mobilized by increased levels of catecholamines and glucagon. Insulin levels are also decreased in the first few days of life.¹ All newborns are observed carefully in the first several hours of life, and most nurseries have nurse-driven protocols in place for testing of those with specific risk factors, because hypoglycemia can be asymptomatic (chemical hypoglycemia) or symptomatic. There is increasing agreement that a glucose level below 50 mg/dL should be treated.^1,2 Oral feeds are attempted first, with either breast milk or formula. Gavage feeds or an intravenous bolus of dextrose is used if necessary. Follow-up testing is done to ensure adequate response. Problems with maintaining glucose homeostasis are related to increased utilization or decreased production of glucose, or increased production of insulin.¹ A complete evaluation is done promptly to determine the cause for hypoglycemia, and if not readily corrected, consultation with a neonatologist is indicated.