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Cortisol, 24-Hour Urinary Free Cortisol (Quantitative)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of cortisol, a stress hormone, that you excrete in your urine over a 24-hour period. It helps assess how well your body produces and regulates cortisol.

Quick summary

["This test helps diagnose conditions related to cortisol imbalance, such as Cushing’s syndrome or adrenal insufficiency."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
26531-4
Short code
Cortis 32h p ACTH SerPl-mCnc
Synonyms
Cortis 32h p ACTH SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
60
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 recommend a 24-hour urine cortisol test if they suspect conditions like Cushing’s syndrome (overproduction of cortisol) or adrenal gland disorders (like Addison’s disease). It’s also used to monitor treatment responses for hormone-related conditions.

How the Test Works

You’ll collect all your urine for a full 24-hour period, typically starting after you’ve urinated at the beginning of the test day. The sample is then sent to a lab for analysis to measure cortisol levels.

Sample Collection

To collect your urine, use a clean container and empty your bladder at the start of the test day. Then, collect every urine sample you pass afterward, including during the night. Keep the samples refrigerated or on ice to preserve cortisol levels.

Preparation

No special preparation is needed, but avoid taking certain medications (like some steroids) that could affect cortisol levels without informing your doctor first.

Reference range

NCBI: ACTH 10-60 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 Might High or Low Cortisol Levels Indicate?
High cortisol levels in urine may suggest Cushing’s syndrome, a tumor affecting the pituitary gland or adrenal glands, or long-term use of steroid medications. Low levels could indicate adrenal insufficiency, where the adrenal glands don’t produce enough cortisol.
How Does This Test Compare to Blood Cortisol Tests?
Unlike blood tests that measure cortisol at specific times (e.g., morning or evening), this test provides a full picture of your cortisol production over a full day, helping detect chronic imbalances that might not show up in single blood measurements.
What If I Missed Collecting Urine?
If you miss any urine during the 24-hour period, you’ll need to restart the collection. If you’re unsure, contact your lab or healthcare provider immediately to avoid inaccurate results.
  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 17, 2026. · Read our editorial policy