Hyperosmolar nonketotic diabetic coma (hyperosmolar nonketotic diabetic coma, referred to as hyperosmolar coma) is another clinical type of acute metabolic disorder of diabetes. It is a clinical syndrome caused by high plasma osmotic pressure, severe dehydration and progressive impaired consciousness, without significant ketoacidosis, often accompanied by varying degrees of neurological manifestations. It is more common in elderly patients with type 2 diabetes, with a high incidence age of 50 to 70 years old. About 2/3 of patients have no history of diabetes before the onset of the disease, or only have mild symptoms. The mortality rate of this disease is very high, with early reports as high as 40% to 70%, and the domestic reported mortality rate is about 50% to 69.2%. Therefore, early detection and timely rescue are the most important.