Osmolality

Osmolality tests measure the amount of certain substances in your blood, urine, or stool (poop). The tests can show how your kidneys are working and whether you have an unhealthy fluid balance.

Osmolality tests may be used for a variety of reasons.

Source: MedlinePlus, U.S. National Library of Medicine

Normal range

≤ 30 d: 50–645 mOsm/kg
17 y+: 50–800 mOsm/kg
30 d – 16 y: 50–1500 mOsm/kg
Normal: 38–1400 mOsm/kg H2O

Ranges from ARUP Laboratories Test Directory, American Board of Internal Medicine (Laboratory Test Reference Ranges).

All 4 source ranges

Source	Sex	Age	Range
American Board of Internal Medicine (Laboratory Test Reference Ranges)	All	all ages	38–1400 mOsm/kg H2O
ARUP Laboratories Test Directory	All	≤ 30 d	50–645 mOsm/kg
ARUP Laboratories Test Directory	All	30 d – 16 y	50–1500 mOsm/kg
ARUP Laboratories Test Directory	All	17 y+	50–800 mOsm/kg

Details

Sample: Urine · LOINC
Listed under: Dehydration · Diabetes Insipidus · Fluid and Electrolyte Balance
Code: LOINC 2695-5 · mOsm/kg H2O
Also known as: Urn, Renal, Observation, Osmolality Ur, Osmo