In acute diabetes conditions, management of the following 3 potential complications is required: diabetic ketoacidosis, hyperosmolar hyperglycemic state, and iatrogenic hypoglycemia. The hyperglycemic crises diabetic ketoacidosis and hyperosmolar hyperglycemic state are the 2 most serious metabolic complications of diabetes. Hypoglycemia, specifically iatrogenic hypoglycemia, results from treatments that raise circulating insulin levels and thus lower plasma glucose concentrations to an abnormally low level, which exposes the patient to potential harm. This article reviews the pathogenesis, precipitating or risk factors, diagnosis or identification, and treatment of these critical complications of diabetes. In addition, a case study on diabetic ketoacidosis is provided.