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Cortisol, Serum, Free (24-Hour Urinary Excretion)

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

This test measures the amount of cortisol (a natural steroid hormone) that you excrete in your urine over 24 hours. It helps assess how well your body produces and balances cortisol, which plays a key role in stress response, metabolism, and immune function.

Quick summary

["This test helps diagnose conditions related to abnormal cortisol levels, such as Cushing’s syndrome or adrenal insufficiency."]

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

Key facts at a glance

LOINC
47847-9
Short code
Cortis p 2 mg Dex high SerPl-sCnc
Synonyms
Cortis p 2 mg Dex high 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
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 this test if they suspect conditions like Cushing’s syndrome (too much cortisol) or adrenal gland problems (too little cortisol). It can also be used to monitor treatment for these conditions or to check for stress-related hormonal imbalances.

What to Expect Before the Test

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

How the Test Works

After collecting your urine sample, it will be analyzed in a lab to measure the total cortisol excreted. This provides a comprehensive picture of your body’s cortisol production over a full day, rather than just a single blood sample.

Test Results and Interpretation

Results are compared to standard reference ranges for healthy individuals. Abnormally high or low levels may indicate underlying health issues that need further evaluation, such as additional blood tests or imaging.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Free Cortisol Urine Test

Frequently asked questions

What does a high cortisol urine test mean?
A high result may indicate conditions like Cushing’s syndrome (caused by excess cortisol from tumors or medications) or chronic stress. Your doctor will review your symptoms and other test results to determine the cause and next steps.
What does a low cortisol urine test mean?
A low result may suggest adrenal insufficiency (where the adrenal glands don’t produce enough cortisol) or other hormonal imbalances. This could be due to autoimmune diseases, long-term steroid use, or other health conditions. Further testing may be needed to identify the exact cause.
How often should I get this test?
Your doctor will determine the frequency based on your symptoms, medical history, and treatment plan. Some patients may need this test periodically to monitor cortisol levels, especially if they’re on long-term medications or managing chronic conditions like Cushing’s syndrome.
  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