The number of people with diabetes is growing to epidemic proportions in the United States. There is a great deal of research on the evolving understanding of the pathogenesis of diabetes as compared to normoglycemia. The diagnostic criteria for diabetes have become streamlined to more appropriately and accurately diagnose the disease. There are millions of people who have diabetes, but do not know it. It is essential that appropriate screening be performed to make a diagnosis in order to delay or prevent the complications from occurring. The complications of diabetes have implications for the increasing number of people with the diagnosis who are hospitalized and how they are treated. There are specific methods for recognition and treatment of both acute and chronic complications in the hospitalized patent with diabetes. Managing blood glucose control is essential for favorable outcomes.