 The precise level of glucose considered low enough to define hypoglycemia is dependent on (1) the measurement method, (2) the age of the person, (3) presence or absence of effects, and (4) the purpose of the definition.While there is no disagreement as to the normal range of blood sugar, debate continues as to what degree of hypoglycemia warrants medical evaluation or treatment, or can cause harm.Deciding whether a blood glucose in the borderline range of 45–75 mg/dL (2.5–4.2 mM) represents clinically problematic hypoglycemia is not always simple.