Cortisol, Serum, Free (24-Hour Urinary)
This test measures the amount of free cortisol, a hormone produced by your adrenal glands, in your urine over a 24-hour period. It helps assess adrenal function and detect 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
- 1434-0
- Short code
- Cortis 8h p 1 mg Dex SerPl-mCnc
- Synonyms
- Cortis 8h p 1 mg Dex 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
- 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 you have symptoms like unexplained weight changes, fatigue, high blood pressure, or signs of hormonal disorders. It’s also used to monitor conditions like Cushing’s syndrome or adrenal gland tumors.
What to Expect Before the Test
For the 24-hour urine collection, you’ll need to collect all urine for a full day, typically starting after waking up and ending before your next morning. Store urine in a refrigerator or at room temperature in a sealed container. Follow your doctor’s instructions precisely to ensure accurate results.
What Happens During the Test
No special preparation is needed for the urine collection itself, but you may be advised to avoid certain medications or foods that could affect cortisol levels. Your doctor will provide detailed instructions on timing and handling the urine samples.
What the Results Mean
Abnormally high or low cortisol levels can indicate underlying health issues. Your doctor will interpret the results in relation to your symptoms and medical history to determine if treatment or further testing is needed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Cortisol plays a key role in managing stress, immune response, and metabolism. Elevated levels may suggest conditions like Cushing’s syndrome (hypercortisolism), while low levels could indicate adrenal insufficiency or other disorders affecting hormone production.
Frequently asked questions
What causes abnormal cortisol levels in urine?
How long does it take to get the results?
Can I take medications before the urine collection?
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