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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

["Evaluates cortisol production and adrenal function over 24 hours."]

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

Key facts at a glance

LOINC
14676-1
Short code
Cortis F 24h Ur-sRate
Synonyms
Cortis F 24h Ur-sRate
Category
hormone
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 (too much cortisol), adrenal insufficiency (too little cortisol), or other hormonal imbalances. It can also help diagnose problems with how your body responds to stress or certain medications.

How the Test Works

You’ll collect urine samples throughout the day in a special container. The test measures the total cortisol excreted in your urine, which reflects your body’s natural cortisol production over time.

Sample Collection Process

You’ll need to collect all urine for 24 hours, typically starting right after waking up and ending just before waking up the next day. Store samples in a refrigerator if not testing immediately. Bring all samples to your lab for testing.

What to Expect Before the Test

No special preparation is usually needed, but avoid taking certain medications (like some steroids) that could affect cortisol levels without discussing it with your doctor first. Stressful events or recent illness may also impact results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24h Urine Cortisol

Frequently asked questions

How long will I need to collect urine for this test?
You’ll need to collect urine for a full 24-hour period, starting right after waking up one morning and ending just before waking up the next morning. This ensures the test captures your cortisol levels over a full day’s cycle.
Can I take medications before this test?
Some medications, especially steroids or others that affect cortisol, may interfere with results. Always check with your doctor before taking any new medications or supplements during your test period.
What if I miss any urine samples during the collection?
If you miss any samples, your test may not be accurate. Follow your doctor’s instructions carefully to ensure complete collection. If you accidentally miss a sample, contact your lab or doctor immediately to discuss rescheduling.
  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