Urinary Creatinine-to-Creatinine Clearance Ratio (or Functional Estimate of Glomerular Filtration Rate)
This test measures how well your kidneys filter waste from your blood, indirectly estimated via urine and blood samples.
["Assesses kidney function by evaluating how efficiently your kidneys remove waste."]
Key facts at a glance
- LOINC
- 29241-7
- Short code
- MuV IgG Fld-aCnc
- Synonyms
- MuV IgG Fld-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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
How the Test Works
Your urine and blood are collected to measure creatinine levels. Creatinine is a waste product naturally produced by muscle metabolism and filtered by the kidneys. The test compares urine creatinine concentration to blood creatinine concentration to estimate kidney function, though it does not directly measure glomerular filtration rate (GFR).
Why It’s Done
Doctors may order this test to check for kidney disease, monitor kidney function in chronic conditions, or assess kidney response to treatments. It can also help evaluate kidney function in people with diabetes or high blood pressure.
What to Expect
You’ll provide a urine sample (typically a 24-hour collection) and a blood sample. The urine sample may be collected over a full day, while the blood sample is drawn in a clinic or lab. Results are usually available within a few days.
Preparation
No special preparation is needed for the blood test, but for the urine sample, follow your healthcare provider’s instructions carefully—such as collecting all urine over 24 hours or timing the sample correctly.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
None
Frequently asked questions
This test helps identify early kidney problems by detecting abnormal waste buildup or filtration inefficiency. It can also track kidney function over time, especially in people with chronic conditions like diabetes or hypertension.
How often should I get this test? Your doctor will determine this based on your health needs. For example, people with kidney disease may need it more frequently than others.
Is there any risk or discomfort? Blood draws are minor and usually painless, while urine collection is simple but may require timing or special containers. Rarely, urine collection errors (e.g., incomplete samples) can affect results.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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