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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 by analyzing your urine.

Quick summary

["Helps assess kidney function and detect early kidney damage or disease."]

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

Key facts at a glance

LOINC
78842-2
Short code
JWH-122 5OH-pentyl CtO Ur Cfm-mCnc
Synonyms
JWH-122 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 Matters

Your kidneys play a vital role in filtering waste and excess fluids from your blood. This test helps doctors determine how efficiently your kidneys are working by measuring the amount of creatinine—a waste product from muscle metabolism—removed from your blood over 24 hours.

What to Expect Before the Test

You’ll collect all your urine for a full 24-hour period, starting after you wake up and ending just before you wake up the next day. Store the urine in a refrigerator to keep it fresh. Your doctor or lab technician will provide detailed instructions to ensure accuracy.

How the Test Works

After collecting your urine sample, it’s sent to a lab where creatinine levels are measured. Creatinine clearance is then calculated by comparing the amount of creatinine in your urine to your blood creatinine levels over the 24-hour period.

What the Results Mean

Lower than expected clearance may indicate kidney problems, while higher values could suggest conditions like dehydration or overhydration. Your doctor will interpret the results in relation to your overall health and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is crucial for diagnosing and monitoring kidney disease, including conditions like chronic kidney disease (CKD), kidney stones, or other renal issues. It helps track how well treatments are working and adjusts care plans accordingly.

Short name

24-Hour Kidney Function Test

Frequently asked questions

Why do doctors order this test?
Doctors may order this test if you have symptoms like fatigue, swelling, frequent urination, or if you have a history of kidney problems, diabetes, or high blood pressure. It’s also used to evaluate kidney function before surgeries or treatments.
What are the normal results?
There are no strict ‘normal’ ranges for creatinine clearance alone, as they depend on factors like age, sex, and body size. Your doctor will compare your results to your baseline or expected values based on your health.
How often should I get this test?
The frequency depends on your health condition. If you have kidney disease, your doctor may recommend regular testing every few months or years. If you’re healthy, it might only be done if you have risk factors or symptoms.
  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