Osmolality, Urine
Also known as: UOSMO
Use
The urine osmolality test measures the concentration of solutes in urine, providing valuable information about the kidney's ability to concentrate or dilute urine. It is a useful test to assess electrolyte and water balance in patients, helping in the diagnosis of conditions like central diabetes insipidus, kidney stones, and dehydration. Evaluating osmolality aids in understanding the underlying causes of abnormal water balance and guides the management of disorders affecting fluid and electrolyte homeostasis.
Special Instructions
Ensure that the urine sample is collected without preservatives. Use an ARUP standard transport tube for submission. Adequate mixing of the urine sample before collecting the aliquot is essential.
Limitations
The test requires urine samples that are free from preservatives. Inaccurate results could arise from samples that have degraded due to improper storage or handling. Unrepresentative urine samples, such as ones collected under improper patient preparation or conditioning, could affect the osmolality readings. It might not account for all solutes present in the urine when compared to more comprehensive diagnostic tests.
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 2695-5
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP standard transport tube
Collection Instructions
Transfer 1 mL aliquot from a well-mixed urine to an ARUP standard transport tube.
Causes for Rejection
Urine collected with preservatives.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 1 week |
| Frozen | 6 months |