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24-Hour Urinary Free Cortisol

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

This test measures the amount of cortisol, a stress hormone, naturally excreted in your urine over a 24-hour period. It helps assess whether your body is producing cortisol at typical or elevated levels.

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
1389-6
Short code
Cortis F 1D p 40 ug ACTH IM 24h Ur-mCnc
Synonyms
Cortis F 1D p 40 ug ACTH IM 24h Ur-mCnc
Category
hormone
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
10
Ref high
60
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 recommend this test if they suspect conditions like Cushing’s syndrome (overproduction of cortisol) or adrenal gland issues (such as adrenal insufficiency). It can also be used to monitor treatment for hormone-related disorders.

How the Test Works

You’ll collect all urine for a full 24 hours, starting after you wake up and ending just before you wake up the next day. The sample is then analyzed to measure cortisol levels in your urine.

Sample Collection

To prepare, empty your bladder before starting and discard the first urine. Collect every urine sample in a container, keeping it refrigerated if possible. Return the sample to your doctor’s office or lab on the same day or within 24 hours.

What to Expect

You’ll receive clear instructions on how to collect your urine sample accurately. Avoid certain medications or foods that might affect cortisol levels before testing.

Reference range

NCBI: ACTH 10-60 pg/mLN/A

Specimen: urine

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.

Clinical Significance

Short name

24h Urine Free Cortisol

Frequently asked questions

What does a high or low result mean?
High cortisol levels in urine may indicate Cushing’s syndrome, a condition where the body produces too much cortisol, often due to a tumor or prolonged steroid use. Low levels could suggest adrenal insufficiency, where the adrenal glands don’t produce enough cortisol.
How often should I get this test?
Your doctor will determine the frequency based on your symptoms, diagnosis, or treatment plan. Follow-up tests may be needed if initial results are abnormal or if you’re being monitored for a hormone-related condition.
Can diet or medications affect this test?
Yes, certain foods, supplements, or medications (like some antidepressants or steroids) can influence cortisol levels. Your doctor will provide specific guidance to avoid these before testing.
  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