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Creatinine Clearance (24-hour urine collection)

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

This test measures how well your kidneys filter waste products, including creatinine, over a full day. It helps assess kidney function and blood flow to the kidneys.

Quick summary

["This test evaluates kidney function by tracking how efficiently your kidneys remove waste over 24 hours."]

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

Key facts at a glance

LOINC
78850-5
Short code
JWH-250 5OH-pentyl CtO Ur Cfm-mCnc
Synonyms
JWH-250 5OH-pentyl CtO Ur Cfm-mCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
confirm
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 they suspect kidney disease, monitor kidney function in chronic conditions, or check for kidney damage after certain treatments or injuries. It’s also used to determine if medications are being properly cleared by your kidneys.

How the Test Works

You’ll collect all your urine for a full 24-hour period in a special container. The test measures creatinine levels in your urine and compares them to a blood sample taken at the start or end of the collection period to calculate clearance.

Sample Collection Process

You’ll receive clear instructions on when to start and stop collecting urine. Drink plenty of fluids but avoid caffeine or medications that may affect results. Return the urine sample and blood sample to the lab on the same day for testing.

What to Expect After the Test

You’ll typically receive results within a few days. Low clearance may indicate kidney problems, while normal results suggest healthy kidney function. Your doctor will discuss the results with you and may recommend follow-up tests if needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24-Hour Urine Creatinine Clearance

Frequently asked questions

What does a low creatinine clearance mean?
A low creatinine clearance may signal impaired kidney function, which can lead to waste buildup in your blood. This could indicate chronic kidney disease, dehydration, or other conditions affecting kidney health. Your doctor will evaluate the results in the context of your overall health.
What if my results are normal?
Normal results suggest your kidneys are filtering waste efficiently. However, this test alone doesn’t rule out early kidney issues. Your doctor may recommend ongoing monitoring or additional tests if they suspect kidney problems.
How often should I get this test?
The frequency depends on your health condition. People with kidney disease or risk factors (like diabetes or high blood pressure) may need this test more often. Follow your doctor’s advice for scheduling.
  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