Differentiating etiologies of Hypernatremia

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aida Javanbakht, M.D.

Overview

Hypernatremia must be differentiated among diseases that cause hypernatremia.

Differentiating Hypernatremia from other Diseases

Disease	Clinical manifestations								Paraclinical Findings
	Symptoms and Signs								Lab Findings
	Confusion/ Irritable	Urine output	Vomiting/ Diarrhea	Volume status	Seizure	Blood pressure	Dry mucous membranes	Other symptoms and signs
									Urine Osm	Serum Na	Other lab findings
Central diabetes insipidus	+	↑	−	↓	+	↑	+	−	<250 mOsm/kg	>170 mEq/L	Low arginine Low vasopressin level
Hyperosmolar hyperglycemia	+	↑	−	↓	+	↓	+	Abdominal pain	Nl	>145 mEq/L	Elevated serum glucose level Elevated creatinine
Nephrogenic diabetes insipidus	+	↑	−	↓	+	↓	+	History of gentamicin, lithium, rifampin use	<250 mOsm/kg	>170 mEq/L	Desmopressin stimulation test: no significant change in urine osmolality
Gastrointestinal loss	+	↓	+	↓	+	↓	+	History of contact with infected food or people	<250 mOsm/kg	>145 mEq/L	Desmopressin stimulation test: not significant change in urine osmolality
Heat stroke	+	↓	−	↓	+	↓	+	Suken eye, sweating	>250 mOsm/kg	>145 mEq/L	Hypokalemia
Essential hypernatremia ( primary hypodipsia)	−	↓	−	↓	−	↓	+	−	>250 mOsm/kg	>145 mEq/L	Low arginine Low vasopressin level
Cushing syndrome	+	↑	−	↓	+	↑	+	Moon face, truncal obesity	Nl	>145 mEq/L	24-hour urinary free cortisol test: >50 microgram
Loop and osmotic diuretic	+	↑	−	↓	+	↓	+	Sunken eye	Nl	>145 mEq/L	Hypokalemia