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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, including creatinine, over a full day. It helps assess kidney function and blood flow to the kidneys.

Quick summary

["Assesses kidney function by evaluating urine output and creatinine clearance over 24 hours."]

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

Key facts at a glance

LOINC
48946-8
Short code
Cocaethylene Spec-mCnc
Synonyms
Cocaethylene Spec-mCnc
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 if they suspect kidney disease, evaluate chronic kidney conditions, or check how well medications are being processed by your kidneys. It’s also used to monitor kidney function in people with diabetes, high blood pressure, or other long-term health issues.

How Is the Test Performed?

You’ll collect all urine for a full 24-hour period in a special container. Your doctor will provide instructions to ensure accuracy. Afterward, the urine sample is sent to a lab for analysis.

What Does the Test Result Mean?

Results are typically reported as a clearance rate (e.g., milliliters per minute or liters per hour). Lower than expected values may indicate kidney problems, while higher values could suggest overhydration or other conditions. Your doctor will interpret results in relation to your overall health.

Common Causes of Abnormal Results

Results may be affected by dehydration, fluid overload, certain medications, or conditions like kidney disease, heart failure, or urinary tract blockages. Always discuss your results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine clearance is a key indicator of kidney function, helping doctors diagnose and manage conditions like chronic kidney disease, acute kidney injury, or evaluate the need for dialysis. It’s also used to determine safe medication dosages for people with impaired kidney function.

Short name

24-Hour Urine Creatinine Clearance

Frequently asked questions

What is creatinine clearance, and how does it differ from other kidney function tests?
Creatinine clearance measures how well your kidneys filter creatinine—a waste product from muscle metabolism—through urine over 24 hours. Unlike blood tests (like serum creatinine), this test reflects kidney function based on urine output, making it more accurate for assessing overall kidney health.
How often should I get this test?
Your doctor will determine how often you need this test based on your health condition, symptoms, and medical history. For example, people with chronic kidney disease may need it every few months, while others may only need it once.
Can I drink fluids before or after the test?
Yes, but follow your doctor’s instructions carefully. Typically, you’ll drink enough fluids to maintain normal urine output throughout the 24-hour period. Avoid excessive fluid intake that could dilute the urine or interfere with results.
  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