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Cortisol, 24-hour urinary free cortisol (mass concentration)

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

This test measures the amount of cortisol, a natural steroid hormone, excreted in your urine over a 24-hour period. It helps assess adrenal gland function and hormone balance.

Quick summary

["This test helps diagnose conditions like Cushing’s syndrome or adrenal insufficiency by checking cortisol levels over a full day."]

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

Key facts at a glance

LOINC
51494-3
Short code
Cortis sp1 p chal Sal-mCnc
Synonyms
Cortis sp1 p chal Sal-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 hormonal imbalances, such as overproduction of cortisol (Cushing’s syndrome) or adrenal gland problems. It’s also used to monitor treatment for conditions affecting cortisol levels.

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 midnight. Collect in a refrigerator to preserve the sample. Your doctor 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 store each portion, mixing it well before each addition. The sample is then sent to a lab for analysis.

What the Results Mean

Abnormally high or low cortisol levels may indicate conditions like Cushing’s syndrome, adrenal tumors, or other hormonal disorders. Your doctor will interpret results in relation to your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Frequently asked questions

How long does the test take to get results?
Results typically take 1–3 business days, depending on lab processing times. Follow-up with your doctor to discuss findings.
Can I eat or drink anything before the test?
No special diet is required, but avoid caffeine or alcohol for 24 hours before collecting urine to avoid influencing results.
Is there any preparation needed besides collecting urine?
Yes, wear comfortable clothing and plan to collect urine at home. If you’re unsure, ask your doctor for guidance.
  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