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HelpTest ID NBLD0061 Cortisol, Free, 24 Hour, Urine
Useful For
Preferred screening test for Cushing syndrome
Diagnosis of pseudo-hyperaldosteronism due to excessive licorice consumption
Test may not be useful in the evaluation of adrenal insufficiency.
Specimen Type
UrineNecessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Supplies: Urine Tubes, 10-mL (T068)
Submission Container/Tube: Plastic urine tube
Specimen Volume: 5 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Add 10 g of boric acid as preservative at start of collection.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
If preservative is not available at your facility, the specimen should be kept refrigerated during collection
and an aliquot should be submitted frozen to Sanford Laboratories in Sioux Falls.
Record the total volume on the specimen and/or requisition if applicable.
24-Hour Urine Collection Instructions English
24-Hour Urine Collection Instructions Spanish
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Specimen Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 28 days | ||
| Ambient | 7 days |
Day(s) Performed
Monday through Friday
Report Available
2 to 6 daysMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82530
Reporting Name
Cortisol, Free, UReference Values
0-2 years: Not established
3-8 years: 1.4-20 mcg/24 h
9-12 years: 2.6-37 mcg/24 h
13-17 years: 4.0-56 mcg/24 h
≥18 years: 3.5-45 mcg/24 h
Use the factor below to convert from mcg/24 hr to nmol/24 hr:
Conversion factor
Cortisol: mcg/24 h x 2.76=nmol/24 hr (molecular weight=362.5)
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.Special Instructions
Secondary ID
8546SANFORD LABORATORY INTERFACE BUILD INFORMATION
| Result Code | Result Code Description |
|---|---|
| 16964 | Cortisol, U |
| 16965 | Collection Duration |
| 16966 | Urine Volume |