Diagnose diabetes mellitus; evaluate disorders of carbohydrate metabolism including alcoholism; evaluate acidosis and ketoacidosis; evaluate dehydration, coma, hypoglycemia, of insulinoma, neuroglycopenia. A fasting glucose >=140 mg/dL on more than one occasion is adequate for the diagnosis of diabetes mellitus. Infants especially with tremor, cyanosis, convulsions, and respiratory distress should have stat glucose, particularly if there is maternal diabetes, postmaturity, asphyxia, hemolytic disease of the newborn, possible sepsis. Babies too large or small for gestational age should also have glucose in the first 24 hours of life. Random blood sugars can be used to monitor therapy in diabetics or evaluate presence of insulinoma.