Glucose counterregulation, the physiological mechanisms that normally very effectively prevent or correct hypoglycemia, involves both dissipation of insulin and activation of glucose counterregulatory (glucose-raising) systems. Glucagon and epinephrine stand high in the hierarchy of redundant counterregulatory factors. Hypoglycemia develops or progresses when both glucagon and epinephrine are deficient and insulin is present despite the actions of other glucose-counterregulatory factors. Growth hormone (like cortisol) is demonstrably involved in defense against prolonged (as opposed to short-term) hypoglycemia, but it is not critical to recovery from even prolonged hypoglycemia or to the prevention of hypoglycemia after an overnight fast. Thus, growth hormone, like cortisol, stands lower in the hierarchy of the redundant glucose-counterregulatory factors.