Hyperglycemic crises in type 2 diabetes are not rare and are becoming increasingly recognized as part of the spectrum of the presentation of previously undiagnosed diabetes mellitus and the decompensation of established diabetes mellitus. Contributing factors and associations are being elucidated but remain far from clear, particularly in DKA states. Medications commonly used in the treatment of many comorbid illnesses in patients with diabetes can themselves predispose to HHS. Endocrinopathies can contribute to insulin resistance and directly increase the glycemic load, leading to hyperglycemia. Medications such as the protease inhibitors may in the future lead to a better understanding of the pathophysiology of the metabolic derangements seen in the development of type 2 diabetes mellitus.