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Urine Creatinine-to-Creatinine Clearance Ratio (or Urine Flow Rate Measurement)

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

This test measures how well your kidneys filter waste products from your blood by analyzing urine flow and creatinine levels. It helps assess kidney function and fluid balance.

Quick summary

["This test helps doctors check how well your kidneys are working and if you’re retaining too much fluid."]

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

Key facts at a glance

LOINC
12010-5
Short code
R-R dur US.meas
Synonyms
R-R dur US.meas
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-measured
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 This Test Is Done

Your doctor may order this test if you have symptoms like swelling, frequent urination, or signs of kidney problems. It can also be used to monitor conditions like chronic kidney disease or fluid overload.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to collect a urine sample over a specific time period (e.g., 24 hours) or provide a single urine sample while urinating at a steady rate.

How the Test Works

The test measures the concentration of creatinine in your urine and how much urine you produce. Creatinine is a waste product from muscle metabolism that kidneys filter out. The ratio helps determine how efficiently your kidneys are working.

What the Results Mean

Results are interpreted by your doctor based on your overall health and symptoms. Abnormal results may indicate kidney dysfunction, dehydration, or other health conditions requiring further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test helps diagnose or monitor kidney function, fluid balance, and conditions affecting urine production. It can also be used to assess hydration status or rule out certain medical issues.

Short name

Urine Flow Rate Test

Frequently asked questions

What causes false high or low results in this test?
False high results may occur if you’re dehydrated, have muscle disorders, or take certain medications. False low results can happen if you’re overhydrated or have kidney disease. Always discuss your medications and health history with your doctor.
How often should I get this test?
Your doctor will determine the frequency based on your health needs. Some people may need it yearly, while others may require it more often if they have chronic conditions like kidney disease.
Can I drink fluids before this test?
Yes, but avoid excessive fluid intake unless instructed otherwise. Follow your doctor’s specific instructions for timing and amount of fluids to ensure accurate 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