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Free cortisol in urine (24-hour collection)

Published: August 9, 2026Updated: August 16, 2026

This test measures how much cortisol (a natural hormone) appears in your urine over 24 hours. It helps check if your body makes too much or too little cortisol.

Quick summary

["Assesses cortisol levels over a full day to diagnose conditions like Cushing’s syndrome or adrenal insufficiency."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
73881-5
Short code
Cortisone free Ur-sCnc
Synonyms
Cortisone free Ur-sCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
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 gain, high blood pressure, mood changes, or unusual fatigue. It’s also used to confirm or rule out conditions affecting your adrenal glands or pituitary gland, which control cortisol production.

How the Test Works

You’ll collect all your urine for a full 24-hour period in a special container. The sample is then sent to a lab to measure cortisol levels. This method gives a more accurate picture than checking cortisol in blood alone.

Sample Collection

Start by emptying your bladder completely at the beginning of the 24-hour period (e.g., midnight). Collect every urine sample you pass afterward, including first-morning urine. Store samples in the fridge if needed. Finish by collecting the last urine sample at the end of the 24 hours.

What to Expect

You’ll need to keep a diary to track when you urinate and how much you produce. Drink plenty of water but avoid caffeine or alcohol, as they can affect results. Follow your doctor’s instructions carefully to ensure accuracy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Urine Free Cortisol

Frequently asked questions

What does a high or low result mean?
High urine cortisol levels may indicate Cushing’s syndrome, where your body produces too much cortisol. Low levels could suggest adrenal insufficiency, where your adrenal glands don’t produce enough cortisol, or other conditions like pituitary tumors.
How is this test different from cortisol blood tests?
Unlike blood tests, which check cortisol levels at one point in time, this 24-hour urine test measures cortisol continuously over a full day. This helps detect patterns of excess or deficiency that might not show up in a single blood sample.
Can I take medications before this test?
Yes, but discuss it with your doctor first. Some medications, like steroids or certain antidepressants, can affect cortisol levels. Your doctor will guide you on whether to adjust your medication or timing.
  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 16, 2026. · Read our editorial policy