Elevated Urine Osmolality

An abnormally increased concentration of osmotically active solutes in urine (normal random specimen: 50-1.200 mOsm/kg, elevated: >850 mOsm/kg), indicating inappropriately concentrated urine due to enhanced renal water reabsorption. Possible causes are dehydration, SIADH, high-protein diet, hyperglycemia (osmotic diuresis), renal failure, and adrenal Insufficiency.