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Creatinine Clearance (from 24-hour urine collection)

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

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

Quick summary

["A measure of kidney function and blood flow over 24 hours."]

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

Key facts at a glance

LOINC
19410-0
Short code
Cocaethylene CtO Ur Cfm-mCnc
Synonyms
Cocaethylene 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 (like diabetes or high blood pressure), or evaluate kidney function before certain treatments. It’s also used to check if kidney dialysis is needed or to determine how well dialysis is working.

How the Test Works

You’ll collect all urine for a full 24-hour period in a container. Blood is drawn at the start and end of the collection to measure creatinine levels in your blood. The test compares how much creatinine appears in your urine versus your blood to calculate clearance.

Sample Collection Process

You’ll need to: • Mark the time you start and stop collecting urine. • Discard the first morning urine (to avoid contamination). • Store all urine in a clean container, mixing it well if needed. • Return the container to your lab with both blood samples (collected at start/end).

What to Expect Before the Test

No special preparation is needed, but drink plenty of water to ensure normal urine flow. Avoid medications that may affect kidney function (like certain pain relievers) unless approved by your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Creatinine Clearance

Frequently asked questions

What does a low or high creatinine clearance mean?
A low creatinine clearance (below 60 mL/min) may indicate kidney damage or disease, while very high values (rare) could suggest dehydration or overhydration. Your doctor will interpret results in the context of your overall health and medical history.
How often should I get this test?
Your doctor will determine the frequency based on your health needs—typically every 3–12 months for stable conditions or more often if kidney function changes.
Can diet affect this test?
Yes, high-protein foods or dehydration can temporarily alter creatinine levels. Your doctor may ask you to follow a standard diet for a few days before testing.
  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