24-Hour Urine Free Cortisol Measurement
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, which is important for managing stress, immune function, and other bodily processes.
["This test helps diagnose conditions related to cortisol imbalance, such as Cushing’s syndrome or adrenal insufficiency."]
Key facts at a glance
- LOINC
- 75516-5
- Short code
- Cortis F 24h Ur-sCnc
- Synonyms
- Cortis F 24h Ur-sCnc
- 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 recommend this test if they suspect an issue with your adrenal glands or pituitary gland, which control cortisol production. It’s also used to monitor conditions like Cushing’s syndrome or to check for abnormal cortisol levels that might not show up in a single blood test.
How the Test Works
You’ll collect all your urine for a full 24-hour period, typically starting and ending at the same time each day. The urine is then sent to a lab for analysis to measure cortisol levels. This method provides a more accurate picture of your cortisol production than a single blood test.
Sample Collection Process
You’ll need to collect every drop of urine for 24 hours, including during sleep. Use a clean container and keep it refrigerated if possible. Your healthcare provider will give you detailed instructions on how to do this correctly.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications or supplements that could affect cortisol levels. Always follow your doctor’s instructions precisely.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
24h Free Cortisol
Frequently asked questions
High cortisol levels over 24 hours may indicate conditions like Cushing’s syndrome, where the body produces too much cortisol. Low cortisol levels could suggest adrenal insufficiency or other hormonal imbalances. This test helps diagnose and monitor these conditions effectively.
The results will be compared to standard ranges to determine if your cortisol levels are within normal limits or if further evaluation is needed.
Common conditions that might lead to this test include suspected Cushing’s syndrome, adrenal insufficiency, or other hormonal disorders affecting cortisol production.
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