Skip to content

Cortisol (24-hour urinary free)

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

This test measures the amount of cortisol, a natural steroid hormone, excreted in your urine over a full day. It helps assess your body’s cortisol production and can help diagnose conditions related to adrenal gland function or stress responses.

Quick summary

["This test helps evaluate cortisol levels over time to detect abnormalities in your body’s natural stress response system."]

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

Key facts at a glance

LOINC
40275-0
Short code
Cortis 45M p chal SerPl-sCnc
Synonyms
Cortis 45M p chal 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 order a 24-hour urine cortisol test if they suspect conditions like Cushing’s syndrome (overactive cortisol production), adrenal insufficiency (underactive cortisol production), or other hormonal imbalances. It can also help monitor treatment effectiveness for conditions affecting cortisol levels.

What to Expect Before the Test

You’ll collect all urine for a full 24-hour period, typically starting after midnight on one day and ending midnight the next. Store urine in a refrigerator until you deliver it to the lab. Follow your doctor’s instructions precisely to ensure accurate results.

During the Test

No special preparation is needed beyond collecting urine samples at home. The lab will analyze the combined urine sample for cortisol content.

What the Results Mean

Results are compared to reference ranges for healthy individuals. Elevated levels may indicate conditions like Cushing’s syndrome, while low levels could suggest adrenal problems or other hormonal disorders. Your doctor will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24-Hour Urine Cortisol

Frequently asked questions

How long does it take to get my results?
Results are typically available within 1 to 2 weeks after the lab processes your sample. Your doctor will contact you once they have the final report.
Can I take medications before this test?
Some medications, like certain steroids or blood pressure drugs, may affect cortisol levels. Always inform your doctor or lab technician about all medications you’re taking before the test.
Is there any dietary restriction before collecting urine samples?
No specific dietary restrictions apply, but avoid excessive caffeine or alcohol in the 24-hour period, as they can influence cortisol levels.
  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