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24-Hour Urinary Free Cortisol

Published: August 9, 2026Updated: August 16, 2026

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, which plays a key role in managing stress, immune response, and metabolism.

Quick summary

["Helps diagnose and monitor conditions linked to cortisol imbalance."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
1407-6
Short code
Cortis 24h p 2 mg Dex SerPl-mCnc
Synonyms
Cortis 24h p 2 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 recommend a 24-hour urinary free cortisol test if they suspect conditions like Cushing’s syndrome (overactive adrenal glands), adrenal insufficiency, or other hormonal imbalances. It can also be used to evaluate stress-related cortisol levels or rule out certain pituitary disorders.

What to Expect Before the Test

You’ll collect your urine for 24 hours, typically starting after midnight on one day and ending midnight the next. Store all urine samples in a refrigerator until you return them to the lab. Follow your doctor’s instructions carefully to ensure accurate results.

How the Test Works

The test measures cortisol levels in your urine, which reflects how much cortisol your body releases over time. Unlike blood tests, this method provides a more comprehensive picture of daily cortisol production, helping identify patterns or abnormalities.

What the Results Mean

Results are compared to standard ranges for healthy adults. High levels may indicate Cushing’s syndrome or other hypercortisolemia conditions, while low levels could suggest adrenal insufficiency or other hormonal deficiencies. 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.

Clinical Significance

Short name

24h Urine Free Cortisol

Frequently asked questions

What causes elevated cortisol levels in urine?
Elevated urinary free cortisol can result from conditions like Cushing’s syndrome (caused by tumors affecting the adrenal glands or pituitary), prolonged use of certain medications (e.g., steroids), or chronic stress. It may also be linked to rare genetic disorders or pituitary adenomas.
What causes low cortisol levels in urine?
Low urinary free cortisol can stem from adrenal insufficiency (Addison’s disease), where the adrenal glands don’t produce enough cortisol, or conditions affecting the pituitary gland (e.g., pituitary tumors or trauma). Chronic stress or certain autoimmune diseases may also contribute.
How often should this test be repeated?
Your doctor may repeat this test if initial results are unclear or if symptoms persist. Frequency depends on your diagnosis, treatment plan, or ongoing health concerns. Follow-up may include additional tests (e.g., blood cortisol levels) or further evaluation by a specialist.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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