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24-Hour Free Cortisol Urine Rate

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

This test measures the amount of cortisol (a natural steroid hormone) excreted in your urine over 24 hours. It helps assess how well your body produces and regulates cortisol, which is important for managing stress, immune function, and other bodily processes.

Quick summary

["Assesses cortisol production and balance over a full day."]

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

Key facts at a glance

LOINC
16668-6
Short code
Cortis F 72h Ur-mRate
Synonyms
Cortis F 72h Ur-mRate
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 issues related to the pituitary gland or adrenal glands, which control cortisol levels.

What to Expect Before the Test

You’ll need to collect all urine for a full 24-hour period, starting right after you wake up and ending just before you wake up the next morning. Store the urine in a refrigerator or cool container, and keep it separate from other urine samples. Your doctor or lab technician will provide detailed instructions.

How the Test Is Performed

The test involves collecting urine samples throughout the day. You’ll use a special container to collect all urine, including during sleep. The samples are combined and sent to a lab for analysis.

What the Results Mean

Results help determine if your body is producing too much or too little cortisol. Abnormal levels may indicate hormonal disorders that require further medical evaluation or treatment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Free Cortisol Urine Rate

Frequently asked questions

How long does it take to get my results?
Results typically take 1 to 2 weeks to be processed and reported by your healthcare provider. Follow-up may be needed if your results are outside expected ranges.
What does it mean if my cortisol levels are too high?
High cortisol levels may suggest conditions like Cushing’s syndrome, which can cause weight gain, fatigue, high blood pressure, or other symptoms. Your doctor will discuss next steps, which may include additional tests or treatments.
Do I need to avoid certain foods or medications before this test?
No special diet or medication restrictions apply for this test. However, follow your doctor’s instructions carefully regarding urine collection and any potential interferences, such as certain medications or supplements.
  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