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Plasma Creatinine Concentration (Rate of Clearance)

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

This test measures how well your kidneys filter waste products from your blood, using creatinine levels and urine flow. It helps assess kidney function and overall health.

Quick summary

["A creatinine clearance test helps doctors check how well your kidneys are working and identify early signs of kidney problems."]

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

Key facts at a glance

LOINC
24441-8
Short code
PPG/Creat Ur-sRto
Synonyms
PPG/Creat Ur-sRto
Category
glucose
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

Creatinine is a waste product naturally produced by your muscles as they work. Healthy kidneys filter it out of your blood and remove it from your body through urine. This test estimates how efficiently your kidneys do this job by comparing creatinine levels in your blood and urine over time.

How the Test Works

You’ll provide a blood sample and a 24-hour urine collection. Blood creatinine levels and urine volume are measured to calculate how quickly creatinine is cleared from your blood.

What to Expect Before the Test

No special preparation is needed for the blood test. For the urine collection, follow your doctor’s instructions carefully—typically, you’ll collect all urine for a full 24-hour period. Drink enough fluids to maintain normal urine output but avoid excessive intake that could dilute results.

Possible Results and Interpretation

Results are compared to standard values based on your age, sex, and body size. Lower-than-expected clearance may indicate kidney problems, while higher-than-expected levels could suggest dehydration or other conditions affecting fluid balance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Clearance

Frequently asked questions

What does a low creatinine clearance mean?
A low creatinine clearance may signal kidney damage or disease, such as chronic kidney disease (CKD), diabetes, or high blood pressure. Early detection helps manage conditions before they worsen.
How often should I get this test?
Your doctor may recommend this test periodically if you have risk factors for kidney problems (e.g., diabetes, hypertension, family history) or if you’re undergoing treatment for conditions that could affect kidney function.
Can diet or medications affect this test?
Yes, certain foods (like red meat) and medications (e.g., NSAIDs like ibuprofen) can temporarily raise creatinine levels. Avoid high-protein foods and certain medications 24 hours before testing, as instructed by your healthcare provider.
  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