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24-Hour Urinary Free Cortisol

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

This test measures the total 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.

Quick summary

["This test helps diagnose adrenal gland issues or cortisol imbalance."]

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

Key facts at a glance

LOINC
25884-8
Short code
Cortis F 24h Ur RIA-sRate
Synonyms
Cortis F 24h Ur RIA-sRate
Category
hormone
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ria
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
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 be used to monitor treatment for conditions affecting cortisol levels.

What to Expect Before the Test

No special preparation is needed. Collect your urine for 24 hours, starting and ending with your first morning urine. Store the urine in a refrigerator until you deliver it to the lab. Follow your doctor’s instructions precisely to ensure accurate results.

How the Test Works

The test measures cortisol levels in your urine by detecting its presence and quantifying the total amount excreted over a full day. This provides a more accurate picture than single-point measurements.

Common Conditions Monitored

This test is often used to diagnose or monitor conditions such as Cushing’s syndrome, adrenal tumors, or congenital adrenal hyperplasia. It can also help evaluate cortisol levels in people with chronic stress, obesity, or other hormonal disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24h Urine Free Cortisol

Frequently asked questions

What does a high or low result mean?
A high result may suggest conditions like Cushing’s syndrome, where the body produces too much cortisol, or certain tumors affecting cortisol production. A low result could indicate adrenal insufficiency or other disorders impairing cortisol synthesis or release. Your doctor will interpret results in the context of your symptoms and medical history.
How often should I get this test?
Your doctor will determine the frequency based on your symptoms, diagnosis, or treatment plan. Some patients may need this test periodically to monitor cortisol levels over time, especially if they’re taking medications that affect cortisol or have conditions requiring long-term management.
Can I take medications before this test?
Yes, you may need to temporarily adjust or stop certain medications (like steroids) as directed by your doctor. Always follow their instructions to avoid interfering with test accuracy. Never stop medications without medical advice.
  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