24-Hour Urinary Free Cortisol
This test measures the amount of cortisol naturally produced by your adrenal glands over a 24-hour period and excreted in your urine. It helps assess whether your body is producing too much or too little cortisol, which can affect stress response and hormone balance.
["Helps diagnose conditions like Cushing’s syndrome or adrenal insufficiency by checking cortisol levels over a full day."]
Key facts at a glance
- LOINC
- 1390-4
- Short code
- Cortis F 2D p 40 ug ACTH IM 24h Ur-mCnc
- Synonyms
- Cortis F 2D p 40 ug ACTH IM 24h Ur-mCnc
- Category
- hormone
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 10
- Ref high
- 60
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Cortisol is a hormone released by your adrenal glands in response to stress, helping regulate metabolism, immune response, and other bodily functions. Measuring cortisol in urine over 24 hours gives a more accurate picture than a single blood test, as it reflects consistent daily production.
What to Expect Before the Test
You’ll collect all your urine for a full 24-hour period, starting after you’ve emptied your bladder at the morning of test day. Store the urine in a refrigerator or at room temperature, and bring all samples to the lab on time. Avoid certain medications (like some steroids) that could affect results.
How the Test Works
The lab analyzes the urine for cortisol levels using a sensitive immunoassay method, which detects cortisol molecules without interference from other substances in urine.
Possible Causes of Abnormal Results
High levels may suggest Cushing’s syndrome (overactive adrenal glands), prolonged stress, or certain medications. Low levels could indicate adrenal gland problems, pituitary issues, or medications that suppress cortisol.
Reference range
NCBI: ACTH 10-60 pg/mLN/A
Typically collected in the morning (8-10 AM). Inform your provider if taking steroid medications.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing conditions like Cushing’s syndrome, adrenal insufficiency, or evaluating chronic stress responses. It helps doctors determine whether hormone therapy or other treatments are needed.
Short name
24h Urine Free Cortisol
Frequently asked questions
Why do I need this test?
What does my result mean?
Can I take medications before the 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 17, 2026. · Read our editorial policy