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24-Hour Urinary Free Cortisol Test

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

This test measures the amount of cortisol, a natural steroid hormone, excreted in your urine over a 24-hour period to help assess cortisol production levels.

Quick summary

["Helps diagnose conditions related to abnormal cortisol levels."]

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

Key facts at a glance

LOINC
26527-2
Short code
Cortis F 72h p ACTH 24h Ur-mCnc
Synonyms
Cortis F 72h p ACTH 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 order this test if you have symptoms like unexplained weight changes, fatigue, mood swings, or signs of either too much (hypercortisolism) or too little (hypocortisolism) cortisol in your body. It can also be used to evaluate conditions like Cushing’s syndrome or adrenal insufficiency.

What to Expect Before the Test

You’ll need to collect all urine for 24 hours, starting and ending with a sample at the same time each day. Store the urine in a refrigerator or freezer to preserve it. Follow your doctor’s instructions carefully to ensure accurate results.

What Happens During the Test

No special preparation is needed beyond collecting urine samples at home. The test involves measuring cortisol levels in your urine, typically analyzed via a chemical method (e.g., immunoassay).

What the Results Mean

Results are compared to standard ranges for cortisol excretion in urine. Elevated levels may suggest conditions like Cushing’s syndrome, while lower levels could indicate adrenal gland issues or other hormonal imbalances.

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 Cortisol

Frequently asked questions

What causes elevated cortisol levels?
Elevated cortisol can result from conditions like Cushing’s syndrome (due to excess hormone production), prolonged stress, certain medications (e.g., steroids), or tumors affecting the pituitary or adrenal glands. Chronic stress or obesity may also contribute.
What causes low cortisol levels?
Low cortisol levels may occur with adrenal insufficiency (e.g., Addison’s disease), severe infections, or prolonged use of certain medications. Autoimmune disorders or genetic conditions can also play a role.
How often should this test be repeated?
Your doctor may repeat this test if initial results are unclear or if symptoms persist. Follow-up testing could involve additional cortisol measurements (e.g., blood tests) or further evaluation of underlying causes.
  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