Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. The chronic hyperglycemia of diabetes mellitus is associated with long-term damage, dysfunction, and failure of various organs, especially the eyes, kidneys, nerves, heart, and blood vessels. The management of this disease process is complicated. Good diabetic control depends on diligence in blood glucose monitoring, frequent adjustment of medications, adherence to a regular diet and exercise plan, and treatment of comorbid conditions such as hypertension and hyperlipidemia.