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Cortisol, 24-Hour Urinary Free Cortisol

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

This test measures the amount of cortisol, a stress hormone, excreted in your urine over a full day. It helps assess how well your body produces and regulates cortisol.

Quick summary

["Helps diagnose adrenal gland disorders or stress-related hormone imbalances."]

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

Key facts at a glance

LOINC
21224-1
Short code
Cortis 2h p chal SerPl-mCnc
Synonyms
Cortis 2h p chal 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 they suspect conditions like Cushing’s syndrome (overproduction of cortisol), adrenal insufficiency (underproduction), or other hormonal imbalances. It can also evaluate chronic stress responses or rule out certain metabolic disorders.

What to Expect Before the Test

You’ll need to collect all urine for a full 24-hour period, typically starting after midnight and ending the next morning. Follow your healthcare provider’s instructions carefully to ensure accurate results. Avoid certain medications or supplements that might affect cortisol levels.

How the Test Works

After collecting urine samples, they’ll analyze the total cortisol excreted in your urine. This method provides an average cortisol level over a day, reflecting natural daily fluctuations.

Possible Results and Interpretation

Results are compared to reference ranges specific to your age, sex, and health status. Abnormally high or low levels may indicate underlying conditions requiring further medical evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Cortisol

Frequently asked questions

What does a high cortisol level mean?
A high urinary cortisol level may suggest conditions like Cushing’s syndrome, where the body produces too much cortisol, or chronic stress. Your doctor may recommend additional tests or treatments to address the cause.
What does a low cortisol level mean?
Low urinary cortisol could indicate adrenal insufficiency, where the adrenal glands don’t produce enough cortisol. This may require hormone replacement therapy or further evaluation of adrenal function.
Can diet or lifestyle affect this test?
Yes, certain foods, supplements, or medications (like some antidepressants or steroids) can influence cortisol levels. Follow your healthcare provider’s instructions to avoid dietary restrictions or medication changes before testing.
  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