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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 from your blood over a 24-hour period using urine samples.

Quick summary

["Helps assess kidney function and filtering efficiency."]

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

Key facts at a glance

LOINC
78844-8
Short code
JWH-200 4OH-indole CtO Ur Cfm-mCnc
Synonyms
JWH-200 4OH-indole 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 Matters

Kidneys play a vital role in removing waste and excess substances from your blood. Creatinine clearance helps doctors determine how effectively your kidneys are doing this job, especially in people with suspected or known kidney problems.

How the Test Works

You’ll collect all your urine over 24 hours in a special container. The lab then analyzes the urine for creatinine levels and compares it to a blood sample taken at the start or end of the period to calculate your kidney function.

What to Expect Before the Test

No special preparation is needed, but you should drink enough fluids to produce urine throughout the day. Avoid taking diuretics (medications that increase urine production) unless instructed by your doctor.

Potential Results and Interpretation

Results are typically reported as a rate (e.g., milliliters per minute or milliliters per hour). Lower than expected values may indicate kidney problems, while higher values could suggest dehydration or other conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24h CrCl

Frequently asked questions

What could my results mean?
A creatinine clearance test is often used to monitor kidney function in people with diabetes, high blood pressure, or other conditions that may affect kidney health. It helps doctors track how well kidneys are working over time and guide treatment decisions.
Can I eat or drink anything special before this test?
No special diet or restrictions are needed. Drink as usual, but make sure to urinate regularly to avoid missing any urine during the collection period.
How long will it take to get my results?
Results are usually available within 1–3 business days after the lab processes your samples. Your healthcare provider will discuss the results with you during your follow-up visit.
  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