Hyperosmolar syndrome in a patient with uncontrolled diabetes mellitus

Nonketotic hyperglycemic hyperosmolar syndrome (HHS) is found mostly in type 2 diabetic patients with marked hyperglycemia. HHS is a metabolic emergency and is associated with a high mortality rate. It is characterized by extreme dehydration and neurologic symptoms, which are related directly to the degree of hyperosmolality. We describe a 65-year-old patient who was admitted because of impaired consciousness caused by HHS. The relevant clinical and laboratory findings are discussed, and a brief overview of the pathophysiology and therapeutic management is provided.