24-Hour Urinary Free Cortisol
This test measures the amount of cortisol, a natural steroid hormone, excreted in your urine over a 24-hour period. It helps assess how well your body produces and regulates cortisol, often used to evaluate conditions like Cushing’s syndrome or adrenal insufficiency.
["This test helps diagnose hormonal imbalances affecting stress response and metabolism."]
Key facts at a glance
- LOINC
- 1391-2
- Short code
- Cortis F 48h p 500 ug Dex 24h Ur-mCnc
- Synonyms
- Cortis F 48h p 500 ug Dex 24h Ur-mCnc
- Category
- hormone
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- 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 Is Done
Your doctor may order a 24-hour urinary cortisol test if they suspect conditions like Cushing’s syndrome (too much cortisol) or adrenal gland problems (too little cortisol). It can also be used to monitor treatment effectiveness for these conditions or other hormonal disorders.
How the Test Works
You’ll collect all your urine for a full 24-hour period, typically starting after a morning void. The urine is stored in a special container, and the sample is sent to the lab for analysis. The test measures cortisol levels in your urine to determine your body’s natural production over time.
What to Expect Before the Test
No special preparation is usually needed, but you’ll need to collect every drop of urine for the full 24 hours. You may be asked to keep a log of when you urinate to ensure accurate timing. Avoid certain medications that could affect cortisol levels, such as some steroids or blood pressure drugs, and discuss this with your doctor beforehand.
What to Expect During the Test
You’ll collect urine in a container at home or at a clinic, depending on your doctor’s instructions. The test involves emptying your bladder into the container at the start of the 24-hour period and continuing to collect all urine until the next morning. The sample is then sent to a lab for analysis.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High cortisol levels in urine may indicate Cushing’s syndrome, a condition caused by prolonged exposure to high amounts of cortisol. Low levels can signal adrenal insufficiency or other hormonal imbalances. This test helps diagnose these conditions and guides treatment decisions, such as medication adjustments or further testing.
Short name
24h Urine Cortisol
Frequently asked questions
How long does it take to get results?
Can I take my usual medications before this test?
What if I miss collecting urine for part of the 24 hours?
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