Cortisol, Serum, Free (24-Hour Urinary Excretion)
This test measures the amount of free cortisol your body excretes in urine over 24 hours. Free cortisol is the active form of the hormone that helps regulate stress responses and other vital functions.
["Assessing cortisol levels helps diagnose conditions related to hormone imbalances or stress responses."]
Key facts at a glance
- LOINC
- 58680-0
- Short code
- Cortis pre 2 mg Dex high SerPl-sCnc
- Synonyms
- Cortis pre 2 mg Dex high SerPl-sCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 20
- Ref high
- 400
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82670
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test to check for conditions like Cushing’s syndrome (overproduction of cortisol) or Addison’s disease (underproduction of cortisol). It can also help evaluate adrenal gland function or rule out other hormonal imbalances. Sometimes, it’s used alongside blood cortisol tests to confirm results.
What to Expect Before the Test
For the 24-hour urine test, you’ll collect all urine for a full day, starting and ending with your first morning urine. Store samples in a refrigerator or freezer to preserve accuracy. Follow your doctor’s instructions carefully to ensure accurate results.
How the Test Works
Free cortisol is naturally present in urine. This test measures the total amount excreted over 24 hours, reflecting your body’s cortisol production and metabolism throughout the day.
What the Results Mean
Results are compared to standard ranges for healthy adults. Elevated levels may indicate conditions like Cushing’s syndrome, while very low levels could suggest adrenal insufficiency or other hormonal disorders. Your doctor will interpret results in the context of your medical history and other tests.
Reference range
Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
What causes elevated cortisol levels in urine?
What causes low cortisol levels in urine?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy