Prototypical patient is elderly with uncontrolled type II DM without adequate access to H2O
Occurs due to 3 factors:
Insulin resistance or deficiency
Increased hepatic gluconeogenesis and glycogenolysis
Osmotic diuresis and dehydration followed by impaired renal excretion of glucose
May result in TBW losses of 8-12L
Ketosis usually absent (may be mild)
Cerebral edema is uncommon complication (case reports)
Estimated mortality 10-20%, usually due to underlying precipitant
In contrast to DKA, in which mortality is 1-5%
Incidence of HHS < 1% of hospital admissions of patients with diabetes
Insulin resistance or deficiency
Increased hepatic gluconeogenesis and glycogenolysis
Osmotic diuresis and dehydration followed by impaired renal excretion of glucose
May result in TBW losses of 8-12L
May result in TBW losses of 8-12L
In contrast to DKA, in which mortality is 1-5%
Incidence of HHS < 1% of hospital admissions of patients with diabetes
Pneumonia (Main)
Urinary tract infection
Medication non-adherence
Cocaine intoxication
Meds: Beta-blockers, diuretics
GI bleed
Pancreatitis
Heat related emergencies
Acute coronary syndrome
Stroke
Hyperosmolar hyperglycemic state
Physiologic stress response 
Cerebral edema in DKA
Diabetes mellitus 
Nonketotic hyperglycemia
Diabetic ketoacidosis
Hyperosmolar hyperglycemic state 
Diabetic ketoacidosis 