{"id":"urine-osmolality","name":"Urine Osmolality","shortName":"Urine Osmolality","aliases":["Osmolality, Urine","U Osm","Osmolality, Random Urine","Urine Osmolality","Osmolality, Urine, Random","Osmolality Urine","Urine Osm","Uosm","Urine Osmolality, Random","Osmolality (Urine)","Osmolality, Random, Urine","Osmolality, Ur"],"abbreviations":["Uosm","U Osm"],"loinc":[{"code":"2695-5","primary":true}],"specimen":"urine","units":[{"ucum":"mosm/kg","display":"mOsm/kg"},{"ucum":"mmol/kg","display":"mmol/kg"}],"referenceRanges":[{"population":"17+","low":50,"high":1400,"unit":"mosm/kg","unitDisplay":"mOsm/kg","note":"Labcorp prints 50 to 1,400 mOsmol/kg for a random urine sample, with no age split. It is shown here for ages 17 and older so that ARUP's age-specific intervals can cover younger ages. Labs differ. ARUP prints a narrower 50 to 800 for ages 17 and older, and the MedlinePlus encyclopedia lists 50 to 1,200 for a random sample. Labcorp also prints 300 to 900 for a 24-hour collection and above 850 after 12 hours of fluid restriction, and Mayo prints 150 to 1,150 for a 24-hour collection from age 12 months. Urine concentration swings with how much you drink, so a result outside the range says more about hydration than about disease. Use the range on your own report first.","sources":[{"title":"Osmolality, Urine (test 003442): sample patient report with reference intervals","url":"https://files.labcorp.com/testmenu-d8/sample_reports/003442.pdf","publisher":"Labcorp"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"How concentrated your urine is, counted as dissolved particles per kilogram of water. It mostly reflects how much you have had to drink and how your kidneys and hormones balance water.","url":"https://bloodtesttracker.com/markers/urine-osmolality","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}