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Cortisol, 24-Hour Urinary Free Cortisol

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 your body’s cortisol production and identify conditions like Cushing’s syndrome or adrenal insufficiency.

Quick summary

["This test helps diagnose hormonal imbalances affecting stress response and metabolism."]

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

Key facts at a glance

LOINC
10332-5
Short code
Cortis pre 250 ug ACTH IM SerPl-mCnc
Synonyms
Cortis pre 250 ug ACTH IM SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
20
Ref high
400
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82670
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 conditions like Cushing’s syndrome (overproduction of cortisol) or adrenal gland disorders (like Addison’s disease). It can also be used to monitor treatment responses for these conditions or evaluate chronic stress-related symptoms.

How the Test Works

You’ll collect all urine produced in a 24-hour period, typically starting after a morning void and continuing until the next morning. The sample is then analyzed to measure cortisol levels in the urine.

Sample Collection Tips

To ensure accurate results, keep the urine sample refrigerated and complete the collection exactly as instructed. Do not miss any urine or add extra fluids unless directed. Avoid certain medications (like some antidepressants or steroids) that may affect cortisol levels.

What to Expect During Testing

You’ll likely need to visit a lab or clinic for urine collection, which may require a few hours of time. No special preparation is needed beyond following the collection instructions precisely.

Reference range

Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A

Specimen: serum

Typically collected in the morning (8-10 AM). Inform your provider if taking steroid medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Cortisol

Frequently asked questions

What causes false high or low results?
False high results may occur if you didn’t collect urine for the full 24 hours, took certain medications, or had recent stress or illness. False low results can happen if you missed urine, had dehydration, or took medications that affect cortisol.
How soon will I get results?
Results are typically available within 1–2 weeks after lab processing, depending on your lab’s workflow. Your doctor will discuss them with you during a follow-up visit.
Can I eat or drink anything before this test?
No special diet is required, but avoid caffeine or alcohol in the 24-hour period to prevent interference with cortisol measurement.
  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