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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 stress hormone, excreted in your urine over a 24-hour period. It helps assess how your body produces and handles cortisol.

Quick summary

["This test helps diagnose conditions related to abnormal cortisol levels, such as Cushing’s syndrome or adrenal insufficiency."]

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

Key facts at a glance

LOINC
77926-4
Short code
Cortis 3M p chal SerPl-sCnc
Synonyms
Cortis 3M p chal SerPl-sCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
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 order this test if they suspect conditions like Cushing’s syndrome (too much cortisol) or adrenal gland issues (too little cortisol). It’s also used to monitor treatment effectiveness for hormone-related disorders.

How the Test Works

You’ll collect all your urine over 24 hours and return it to the lab. The lab measures cortisol levels in your urine to see how much your body naturally produces and excretes.

Sample Collection Tips

To get accurate results, follow your healthcare provider’s instructions carefully. Typically, you’ll start collecting urine at a specific time (often midnight) and continue until the next day’s midnight. Store urine in a cool place and keep it refrigerated if needed.

What to Expect Before the Test

No special preparation is usually needed, but avoid taking certain medications that might affect cortisol levels without discussing it with your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Cortisol

Frequently asked questions

How long does it take to get results?
Results are typically ready within 1–2 weeks after the lab processes your sample, depending on lab workload.
Can I drink alcohol before this test?
Alcohol may not significantly affect cortisol levels in this test, but it’s best to avoid it for consistency. Always confirm with your doctor or lab technician.
Does diet affect this test?
Dietary changes unrelated to stress (like high-sodium foods) are unlikely to impact cortisol levels in urine. However, avoid extreme stress or illness during collection to ensure accuracy.
  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