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24-Hour Urine Collection for Creatinine Clearance

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

This test measures how well your kidneys filter waste products from your blood by collecting your urine over 24 hours. It helps assess kidney function and blood pressure management.

Quick summary

["Assesses kidney function and blood pressure control through urine waste clearance."]

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

Key facts at a glance

LOINC
95884-3
Short code
Date data collected for Report
Synonyms
Date data collected for Report
Category
chemistry
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 Is This Test Done?

Your doctor may order this test to evaluate kidney health, especially if you have high blood pressure, diabetes, or signs of kidney problems like reduced urine output or swelling. It also helps monitor kidney function before surgeries or treatments that may affect kidneys.

What to Expect Before the Test

You’ll need to collect all urine for 24 hours, starting after midnight on one day and ending immediately after midnight the next. Use a clean container to store the urine. Drink plenty of water to help your kidneys produce urine, but avoid excessive caffeine or diuretics unless instructed otherwise.

What Happens During the Test?

No special procedure is needed during the test. You’ll be provided with a collection container and instructions. Simply empty your bladder into the container every time you urinate, including first-morning urine. Store the urine in a cool place until the 24-hour period is complete.

What Happens After the Test?

After completing the collection, return the urine sample to your lab or doctor’s office. They’ll analyze the urine for creatinine levels and calculate your creatinine clearance rate. You can resume your normal activities once the test is finished.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Clearance (24h Urine)

Frequently asked questions

How long does the 24-hour urine collection take?
The entire process takes exactly 24 hours, from midnight to midnight. You’ll need to consistently collect all urine produced during this period.
What should I do if I miss a part of the collection?
If you miss any urine output, you should restart the collection immediately and include all urine produced from that time onward. Notify your healthcare provider right away to avoid inaccurate results.
Can I take my usual medications during the urine collection?
Yes, you can take your usual medications unless your doctor instructs otherwise. However, avoid excessive diuretics or caffeine unless approved, as they may affect urine volume.
  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