Cortisol, Serum, Free (24-Hour Urinary)
This test measures the amount of free cortisol (a form of cortisol not bound to proteins) excreted in your urine over 24 hours. It helps assess how well your body produces and regulates cortisol, a hormone involved in stress response and metabolism.
["This test helps diagnose conditions like Cushing’s syndrome or adrenal insufficiency by checking cortisol levels outside the bloodstream."]
Key facts at a glance
- LOINC
- 93483-6
- Short code
- Cortis 2M p 1 ug/kg CRH IV SerPl-mCnc
- Synonyms
- Cortis 2M p 1 ug/kg CRH IV SerPl-mCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 86701
- 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 if they suspect hormonal imbalances, such as overproduction of cortisol (Cushing’s syndrome) or adrenal gland problems (e.g., Addison’s disease). It can also be used to monitor treatment effectiveness for conditions linked to cortisol.
How the Test Works
You’ll collect all urine for a full 24-hour period in a special container. The sample is then sent to a lab for analysis using a sensitive method to measure free cortisol levels.
What to Expect Before the Test
No special preparation is needed, but you should drink enough fluids to produce urine throughout the day. Avoid taking medications that may affect cortisol levels without consulting your doctor.
What to Expect During the Test
You’ll collect urine in a container for 24 hours, changing it every time you urinate. The test is non-invasive and doesn’t require a blood draw.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cortisol is a hormone produced by the adrenal glands in response to stress. Abnormal levels can cause symptoms like weight changes, fatigue, or mood swings. High cortisol may indicate overactive adrenal glands, while low levels may signal adrenal insufficiency or other endocrine disorders.
Short name
Free Cortisol Urine Test
Frequently asked questions
Why might my doctor recommend this test?
What do my results mean?
Can I take medications before 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