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Test ID CORTU 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

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Cortisol, Free, U

Specimen Type

Urine


Necessary Information


24-Hour volume 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 in Special Instructions for multiple collections.


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

Reference Values

0-2 years: not established

3-8 years: 1.4-20 mcg/24 hours

9-12 years: 2.6-37 mcg/24 hours

13-17 years: 4.0-56 mcg/24 hours

≥18 years: 3.5-45 mcg/24 hours

 

Use the factor below to convert from mcg/24 hours to nmol/24 hours:

 

Conversion factor

Cortisol: mcg/24 hours x 2.76=nmol/24 hours (molecular weight=362.5)

 

For SI unit Reference Values, see https://www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Day(s) Performed

Monday through Friday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82530

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CORTU Cortisol, Free, U 43126-2

 

Result ID Test Result Name Result LOINC Value
8546 Cortisol, U 14158-0
TM93 Collection Duration 13362-9
VL47 Urine Volume 3167-4

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

Report Available

2 to 5 days

NY State Approved

Yes

Urine Preservative Collection Options

Note: The addition of preservative must occur prior to the start of the collection or application of temperature controls must occur during collection.

Ambient

No

Refrigerate

OK

Frozen

OK

50% Acetic Acid

OK

Boric Acid

Preferred

Diazolidinyl Urea

No

6M Hydrochloric Acid

No

6M Nitric Acid

No

Sodium Carbonate

No

Thymol

No

Toluene

No