Severe illness can cause hyperglycemia even in those patients who do not have an antecedent diagnosis of diabetes mellitus.[16] Severe stress (as during a serious illness such as severe burns) is accompanied by significant increases in the plasma concentrations of counterregulatory hormones (i.e., glucagon, epinephrine, cortisol, and growth hormone) and cytokines. Here, GCG is linked to diabetes mellitus.