This document summarizes acute complications of diabetes, including diabetic ketoacidosis (DKA), hyperglycemic hyperosmolar state (HHS), and hypoglycemia. It notes that DKA and HHS are caused by absolute or relative insulin deficiency with excess counterregulatory hormones, and presents symptoms like polyuria, nausea, and altered mental status. The document contrasts DKA and HHS, noting DKA primarily affects type 1 diabetics and is characterized by ketosis, while HHS usually affects elderly type 2 diabetics and presents without ketosis. Management of both involves fluid replacement and treatment of the underlying causes.