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Cortisol, 24-Hour Urinary Free

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

This test measures the amount of cortisol naturally produced by your body and excreted in your urine over a 24-hour period.

Quick summary

["Assesses long-term cortisol levels to help diagnose conditions like Cushing’s syndrome or adrenal insufficiency."]

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

Key facts at a glance

LOINC
58548-9
Short code
ACTH 15M p Ins IV Plas-sCnc
Synonyms
ACTH 15M p Ins IV Plas-sCnc
Category
hormone
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
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 this test if they suspect hormonal imbalances affecting your cortisol levels, such as overproduction (Cushing’s syndrome) or underproduction (adrenal insufficiency). It helps evaluate conditions like chronic stress, certain tumors, or other endocrine disorders.

How the Test Works

You’ll collect all urine for a full 24-hour period in a sterile container. The sample is then sent to a lab for analysis to measure cortisol concentration.

Sample Collection

To ensure accurate results, collect urine starting immediately after waking up and continue until you wake up the next morning. Store samples in a refrigerator if not tested right away.

Preparation

No special preparation is needed, but avoid taking certain medications (like some steroids) that could affect cortisol levels unless instructed by your doctor.

Reference range

NCBI: ACTH 10-60 pg/mLN/A

Specimen: plasma

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.

Elevated cortisol levels may indicate conditions like Cushing’s syndrome, chronic stress, or certain tumors. Low levels could signal adrenal gland problems, such as Addison’s disease. This test helps diagnose and monitor these conditions by providing a comprehensive picture of your body’s cortisol output over time.

Short name

24-Hour Urine Cortisol

Frequently asked questions

What Does a High Cortisol Level Mean?
High cortisol in urine may suggest overactive adrenal glands, prolonged stress, or certain medications. Your doctor will review your symptoms and other test results to determine the cause.
What Does a Low Cortisol Level Mean?
Low cortisol levels may indicate adrenal insufficiency, autoimmune disorders, or other health issues affecting hormone production. Further evaluation, including blood tests or imaging, may be needed.
How Often Should I Get This Test?
Your doctor will decide how often to repeat this test based on your symptoms, medical history, and previous results. Follow-up may be needed if initial results are abnormal or unclear.
  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