Cortisol, 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 cortisol production and identify conditions related to adrenal gland function.
This test helps diagnose or monitor adrenal gland disorders, including Cushing’s syndrome or Addison’s disease.
Key facts at a glance
- LOINC
- 58659-4
- Short code
- Cortis 2h p 1 ug/kg CRH IV SerPl-sCnc
- Synonyms
- Cortis 2h p 1 ug/kg CRH IV SerPl-sCnc
- 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 is this test done?
Your healthcare provider may order this test if you have symptoms like unexplained weight gain, fatigue, high blood pressure, or changes in your mood or sleep patterns. It may also be used to check for conditions affecting cortisol levels, such as Cushing’s syndrome (too much cortisol) or Addison’s disease (too little cortisol).
What to expect before the test
You’ll collect your urine for 24 hours, starting from the first morning urine after waking up until the same time the next day. Store the urine in a refrigerator or a cool place until you deliver it to the lab. Follow your provider’s instructions carefully to ensure accurate results.
What happens during the test
No special preparation is needed beyond collecting your urine over a full 24-hour period. The lab will analyze the urine sample to measure cortisol levels.
Possible results and next steps
Results will be compared to standard ranges to determine if your cortisol levels are too high or too low. Your healthcare provider will discuss the results with you and may recommend further testing or treatment based on your symptoms and findings.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated cortisol levels may indicate conditions like Cushing’s syndrome, which can cause weight gain, muscle weakness, and high blood pressure. Low cortisol levels may suggest Addison’s disease, leading to fatigue, low blood pressure, and salt cravings. This test is crucial for diagnosing and managing these conditions early.
Frequently asked questions
How often should I get this test?
What does it mean if my cortisol levels are high?
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