Reactions that usually are regarded as hypoglycemic in origin quite frequently complicate the treatment of diabetic patients receiving insulin. When these are relieved by simple alteration in diet or insulin dosage, they do not become a matter of undue concern to either the patient or the physician. On the other hand, when they fail to be controlled satisfactorily by such measures, their management presents a perplexing problem. The lack of correlation that may occur between the clinical manifestations of reactions and the blood glucose level1 adds further to the confusion. Reactions of the latter type—where characteristic symptoms occur in the presence of normoglycemia or hyperglycemia—have been referred to as pseudohypoglycemic reactions.2 The mechanism for these is not completely understood. Most investigators have sought to relate them to the physiology of diabetes mellitus and have postulated that they are due to some disturbance in the availability, transportation, or utilization