24-Hour Urinary Free Cortisol
This test measures how much cortisol, a stress hormone, is excreted in your urine over a full day. It helps assess adrenal gland function and detect conditions like Cushing’s syndrome or adrenal insufficiency.
["Helps diagnose hormonal imbalances linked to stress or adrenal disorders."]
Key facts at a glance
- LOINC
- 3241-7
- Short code
- Fact XIII Clot Dis 24h PPP Ql
- Synonyms
- Fact XIII Clot Dis 24h PPP Ql
- Category
- chemistry
- Sample
- plasma
- Container
- Lavender-top (EDTA) or Green-top (Heparin)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- coag
- 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 Matters
Cortisol is a key hormone produced by your adrenal glands, which sit on top of your kidneys. It helps your body respond to stress, regulate blood pressure, and control metabolism. Measuring cortisol in urine over 24 hours gives a fuller picture of your body’s natural cortisol levels, which can be affected by daily stress, medications, or health conditions.
How the Test Works
You’ll collect your urine for a full day, typically starting after you wake up and ending the next morning. The sample is then analyzed to measure the total cortisol excreted. This method avoids fluctuations that can occur with blood or saliva tests.
What to Expect Before the Test
No special preparation is needed, but avoid taking certain medications (like some steroids) that could affect cortisol levels. If you’re on long-term medications, discuss this with your doctor first. Drink plenty of water to help your kidneys pass the cortisol properly.
What to Expect During the Test
You’ll collect all urine for 24 hours in a special container. Some clinics provide a kit with instructions. Make sure to start and end the collection at the same time each day to ensure accuracy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High cortisol levels in urine may indicate Cushing’s syndrome (overproduction of cortisol), which can cause weight gain, fatigue, or high blood pressure. Low cortisol levels could signal adrenal insufficiency, where the body struggles to produce enough cortisol to handle stress. This test is also used to monitor treatment effectiveness for conditions like Addison’s disease or to check for cortisol-related side effects from medications.
Short name
24h Free Cortisol Urine
Frequently asked questions
How does the 24-hour urine test differ from cortisol blood tests?
Can I take over-the-counter medications before this test?
What if I miss part of 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