Cortisol, 24-Hour Urinary Free
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.
["This test helps diagnose adrenal gland issues or cortisol imbalance."]
Key facts at a glance
- LOINC
- 1433-2
- Short code
- Cortis 72h p 500 ug Dex SerPl-mCnc
- Synonyms
- Cortis 72h p 500 ug 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 a 24-hour urine cortisol test if they suspect conditions like Cushing’s syndrome (overactive adrenal glands producing too much cortisol), adrenal insufficiency (underactive adrenal glands), or other hormonal imbalances. It can also help monitor treatment effectiveness for conditions linked to cortisol levels.
What to Expect Before the Test
You’ll collect all urine for 24 hours, starting from the first void after midnight of the day before testing until the first void the following midnight. Keep the urine in a refrigerator or cool container to preserve it. Do not miss any urine, including the first and last samples.
During the Test
No special preparation is needed beyond the 24-hour urine collection. The lab will analyze the sample for cortisol levels. Results are typically reported as the total cortisol excreted in micrograms (mcg) over 24 hours.
What the Results Mean
Higher-than-expected cortisol levels may indicate Cushing’s syndrome or other causes of chronic cortisol excess. Lower-than-expected levels may suggest adrenal insufficiency or other conditions affecting cortisol production. Your doctor will interpret results in the context of your symptoms and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal cortisol levels detected through this test can guide treatment for hormonal disorders, help diagnose conditions affecting the adrenal glands, or evaluate the effectiveness of medications that influence cortisol production. It’s a key diagnostic tool for conditions like hypercortisolism or hypocortisolism.
Short name
24-Hour Urine Cortisol
Frequently asked questions
What causes false high or low results?
How long does it take to get results?
Can I drink alcohol 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