A diagnosis of diabetic ketoacidosis (DKA) requires the patient’s plasma glucose concentration to be above 250 mg per dL (although it usually is much higher), the pH level to be less than 7.30, and the bicarbonate level to be 18 mEq per L or less.
The hyperosmolar hyperglycemic state (HHS) is the most serious acute hyperglycemic emergency in patients with type 2 diabetes, characterized by severe hyperglycemia and glycosuria in the absence of Kussmaul breathing, with a fruity breath odor or positive acetone test in the urine. Current diagnostic HHS criteria include a plasma glucose level >600 mg/dL and increased effective plasma osmolality >320 mOsm/kg in the absence of ketoacidosis.
Diagnostic Criteria for Diabetic Ketoacidosis and Hyperosmolar Hyperglycemic State
| Mild DKA | Moderate DKA | Severe DKA | HHS | |
| Plasma glucose (mg per dL [mmol/L]) | > 250 (13.9) | > 250 | > 250 | 600 (33.3) |
| Arterial pH | 7.25 to 7.30 | 7.00 to 7.24 | < 7.00 | > 7.30 |
| Serum bicarbonate (mEq/L) | 15 to 18 | 10 to < 15 | < 10 | > 15 |
| Urine ketones | Positive | Positive | Positive | Small |
| Serum ketones | Positive | Positive | Positive | Small |
| Beta-hydroxybutyrate | High | High | High | Normal or elevated |
| Effective serum osmolality (mOsm/kg)* | Variable | Variable | Variable | > 320 |
| Anion gap† | > 10 | > 12 | > 12 | Variable |
| Alteration in sensoria or mental obtundation | Alert | Alert/drowsy | Stupor/coma | Stupor/coma |
*Effective serum osmolality = 2 × measured Na (mEq/L) + (glucose [mg/dL] ÷ 18).
†Anion gap = Na+ – (Cl– + HCO3– [mEq/L]).
References:
- Karslioglu French E, Donihi AC, Korytkowski MT. Diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome: review of acute decompensated diabetes in adult patients. BMJ. 2019 May 29;365:l1114. [Medline]
- Pasquel FJ, Umpierrez GE. Hyperosmolar hyperglycemic state: a historic review of the clinical presentation, diagnosis, and treatment. Diabetes Care. 2014 Nov;37(11):3124-31. [Medline]
- Fayfman M, Pasquel FJ, Umpierrez GE. Management of Hyperglycemic Crises: Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar State. Med Clin North Am. 2017 May;101(3):587-606. [Medline]
- Trachtenbarg DE. Diabetic ketoacidosis. Am Fam Physician. 2005 May 1;71(9):1705-14. [Medline]
- Abady E, Tamvakologos PI, Mourid MR, Abdelrahman ST, Aziz MM, Rath S, Carr LA, Alsabri M. A narrative review of the diabetic ketoacidosis and hyperosmolar hyperglycemic state overlap syndrome. Int J Emerg Med. 2025 Nov 21;18(1):244. [Medline]
Created Oct 15, 2020.
Up-date Jan 07, 2026.
