Abstract
Introduction: Diabetes Mellitus is a chronic disease that will be suffered for a lifetime so the progressive disease will continue and can cause complications. Diabetes mellitus usually progresses slowly with symptoms that are mild to severe and can even cause death due to acute or chronic complications.
 
 Content: Hyperglycemic crisis is one of the acute complications that can occur in Diabetes mellitus, both type 1 and type 2. This situation is a serious complication that may occur even in well-controlled diabetes mellitus.
 Conclusion: Diabetic ketoacidosis and hyperglycemic Hyperosmolar State are acute complications of Diabetes mellitus. Both of these complications can be triggered due to inadequate insulin therapy and the presence of infection. Diabetic ketoacidosis is a condition characterized by metabolic acidosis due to excessive formation of ketones, while a hyperglycemic hyperosmolar state is characterized by severe hyperosmolality with serum glucose levels which are usually higher than diabetic ketoacidosis.