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Cortisol, 24-hour urinary free cortisol

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

This test measures the amount of cortisol, a natural steroid hormone, excreted in your urine over a full day. It helps assess adrenal gland function and hormone balance.

Quick summary

["This test checks if your adrenal glands are producing enough cortisol, often used 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
1400-1
Short code
Cortis 1h p 1 ug/kg CRH IV SerPl-mCnc
Synonyms
Cortis 1h p 1 ug/kg CRH IV SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86701
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 you have symptoms like unexplained weight gain, fatigue, high blood pressure, or unusual hair growth. It’s also used to diagnose or monitor conditions affecting cortisol levels, such as Cushing’s syndrome or Addison’s disease.

What to Expect Before the Test

You’ll collect all urine produced in a 24-hour period (from one morning to the next morning). Drink plenty of water to help flush cortisol into your urine. Avoid certain medications that might affect cortisol levels, like some steroids, without consulting your doctor.

How the Test Works

The collected urine is tested for cortisol levels using a sensitive laboratory method. This helps determine whether your body is producing too much or too little cortisol over time.

Possible Results and Interpretation

Results are compared to standard ranges, though exact values can vary by lab. High levels may suggest conditions like Cushing’s syndrome, while low levels could indicate adrenal insufficiency or other hormonal imbalances. Your doctor will discuss these results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24-Hour Urine Cortisol

Frequently asked questions

What does a high cortisol level mean?
A high urinary cortisol level may indicate overproduction of cortisol by your adrenal glands, which can be caused by conditions like Cushing’s syndrome (often due to a tumor) or long-term use of certain medications. It can also be seen in stress-related conditions or certain cancers.
What does a low cortisol level mean?
Low urinary cortisol levels often suggest adrenal insufficiency, where your adrenal glands aren’t producing enough cortisol. This can be due to autoimmune diseases, infections, or long-term steroid use. It may also be seen in conditions affecting the pituitary gland or hypothalamus.
How often should I get this test?
This test is typically done once or twice to confirm results. Your doctor may recommend follow-up testing if initial results are abnormal or if symptoms persist, depending on your diagnosis and treatment plan.
  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