Osmolality (urine)

Urine_electrolyte Unit: mOsm/kg Urine test

Measure of kidney concentrating/diluting ability

Also known as: Urine Osmolality

Reference Ranges

Clinical Reference 300.0 – 900.0 mOsm/kg

Optimal Range 400.0 – 800.0 mOsm/kg

Reflects concentrating ability; compare to serum

Dehydration High

Diabetes Insipidus Low

🍎 Food Increase fluid intake — concentrated urine indicates dehydration High urine osmolality with high serum osmolality = dehydration

🍎 Food If not drinking excess water, seek medical evaluation for concentrating defect Low urine osmolality with high serum = diabetes insipidus

🍎 Food Reduce excess fluid intake; check for medications affecting ADH Dilute urine often reflects overhydration

Does my low urine osmolality indicate a problem with kidney concentrating ability? Inability to concentrate urine suggests diabetes insipidus or CKD; compare with serum osmolality.
Could this reflect dehydration or SIADH? Concentrated urine workup

Upload your blood test to see how your Osmolality (urine) compares to reference and optimal ranges.