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24-Hour Urinary Free Cortisol

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

This test measures how much cortisol your body excretes naturally over a full day in your urine. It helps assess whether your adrenal glands are producing enough cortisol, which is important for managing stress, immune function, and other bodily processes.

Quick summary

["This test helps diagnose adrenal gland issues or cortisol imbalance."]

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

Key facts at a glance

LOINC
1409-2
Short code
Cortis 24h p 500 ug ACTH IM SerPl-mCnc
Synonyms
Cortis 24h p 500 ug ACTH IM 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 Matters

Cortisol is a hormone produced by your adrenal glands that helps your body respond to stress. Measuring urinary cortisol over 24 hours gives a more accurate picture than a single blood test, as it reflects your body’s natural cortisol output throughout the day.

What to Expect Before the Test

You’ll collect all your urine for a full 24-hour period, starting right after you wake up. Store the urine in a refrigerator until you return it to the lab. Do not add preservatives unless instructed.

How the Test Works

Your urine sample is analyzed to measure the amount of cortisol excreted. The test uses a sensitive method to detect cortisol levels, ensuring accurate results for diagnosing conditions like Cushing’s syndrome or adrenal insufficiency.

Possible Conditions It Can Help Identify

This test can help diagnose conditions such as Cushing’s syndrome (too much cortisol), adrenal insufficiency (too little cortisol), or other hormonal imbalances linked to cortisol levels.

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.

Clinical Significance: Cortisol plays a key role in metabolism, immune response, and stress regulation. Abnormal levels may indicate adrenal disorders, chronic stress, or other health concerns that require medical evaluation.

Short name

24h Urine Free Cortisol

Frequently asked questions

Why is my doctor ordering this test?
Your doctor may recommend this test if they suspect hormonal imbalances, such as Cushing’s syndrome or adrenal gland problems, or if you have symptoms like weight changes, fatigue, or unexplained stress responses.
What do my results mean?
Results are compared to standard ranges, but your doctor will interpret them in the context of your symptoms and medical history. High levels may suggest overproduction of cortisol, while low levels may indicate adrenal insufficiency.
Can I take medications before this test?
Some medications, like steroids or certain blood pressure drugs, may affect cortisol levels. Always follow your doctor’s instructions about timing and whether to discontinue any medications beforehand.
  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