Contributor: Aaron Lessen, MD Educational Pearls: Hyperglycemic Hyperosmolar State (HHS) is less common than Diabetic Ketoacidosis (DKA) but is associated with a mortality rate up to 10 times greater than that seen in DKA Typically seen in elderly patients with severely elevated blood glucose levels (>1000 mg/dL) and an increased plasma osmolality Unlike in DKA, patients with HHS do not have elevated ketones Treatment of HHS includes insulin administration along with correcting fluid and electrolyte abnormalities When treating HHS, it is important to monitor and follow osmolality regularly because over-rapid correction can result in the development of cerebral edema References Fayfman M, Pasquel FJ, Umpierrez GE. Management of Hyperglycemic Crises: Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar State. Med Clin North Am. 2017;101(3):587-606. Gosmanov AR, Gosmanova EO, Kitabchi AE. Hyperglycemic Crises: Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar State. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext. South Dartmouth (MA): MDText.com, Inc. Copyright © 2000-2022, MDText.com, Inc.; 2000. Long B, Willis GC, Lentz S, Koyfman A, Gottlieb M. Diagnosis and Management of the Critically Ill Adult Patient with Hyperglycemic Hyperosmolar State. J Emerg Med. 2021;61(4):365-375.   Summarized by Mark O’Brien, MS4 | Edited by John Spartz MS4 & Erik Verzemnieks, MD   The Emergency Medical Minute is excited to announce that we are now offering AMA PRA Category 1 credits™ via online course modules. To access these and for more information, visit our website at https://emergencymedicalminute.org/cme-courses/ and create an account.  Donate to EMM today!