Skip to content

Cortisol, 24-hour urinary free

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. It helps assess adrenal gland function and hormone balance.

Quick summary

["This test helps diagnose adrenal disorders or hormone imbalances by tracking cortisol levels naturally excreted in urine."]

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

Key facts at a glance

LOINC
58552-1
Short code
ACTH 15M pre Ins IV Plas-sCnc
Synonyms
ACTH 15M pre 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 a 24-hour urine cortisol test if they suspect conditions like Cushing’s syndrome (excess cortisol), adrenal insufficiency (low cortisol), or other hormonal imbalances. It provides a full picture of cortisol production over a full day, unlike single-point blood tests.

What to Expect Before the Test

You’ll collect all urine for 24 hours, starting after midnight of the first day and ending just before midnight the next day. Keep a record of the time each urine sample is collected. Drink plenty of fluids to ensure full collection, but avoid caffeine or medications that may affect cortisol levels.

What Happens During the Test

No special preparation is needed beyond collecting urine samples in a sterile container at each time point. The samples are sent to a lab for analysis, typically using a method like immunoassay or chromatography to measure cortisol concentration.

What the Results Mean

Results are compared to standard ranges for healthy individuals. Elevated levels may indicate overproduction of cortisol, while low levels may suggest adrenal problems. Your doctor will interpret results in the context of your symptoms and other tests.

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.

Clinical Significance

Short name

24-Hour Urine Cortisol

Frequently asked questions

What causes high cortisol levels in urine?
High urinary cortisol can result from conditions like Cushing’s syndrome (due to excess cortisol from tumors or prolonged steroid use), stress, or certain medications. It may also be linked to pituitary or adrenal gland tumors.
What causes low cortisol levels in urine?
Low urinary cortisol often points to adrenal insufficiency (e.g., Addison’s disease), where the adrenal glands fail to produce enough cortisol. It can also occur with chronic stress, autoimmune diseases, or certain medications.
How often is this test repeated?
Your doctor may repeat the test if initial results are unclear or if symptoms persist. Follow-up tests might include blood cortisol levels, imaging, or other hormonal assessments to confirm or refine the diagnosis.
  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