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Urine Creatinine-to-Creatinine Clearance Ratio (24-hour urine collection)

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

This test measures how well your kidneys filter waste products from your blood by analyzing urine and blood creatinine levels over 24 hours.

Quick summary

["Helps assess kidney function and blood flow through the kidneys over time."]

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

Key facts at a glance

LOINC
46137-6
Short code
Tri-Phos Cry #/area UrnS HPF
Synonyms
Tri-Phos Cry #/area UrnS HPF
Category
electrolyte
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
microscopy-light-hpf
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 Is Done

Your doctor may order this test if they suspect kidney disease, evaluate chronic kidney conditions, or check for issues with how well your kidneys remove waste. It can also help monitor treatments for kidney-related problems.

How the Test Works

You’ll collect all urine for 24 hours in a special container. Blood is drawn once to measure creatinine levels. The ratio of creatinine in urine to blood helps estimate how efficiently your kidneys filter waste.

Sample Collection Process

You’ll start the collection immediately after waking up, empty your bladder first, then collect every urine void for 24 hours. Store urine in a refrigerator if needed. Bring all urine samples and the blood sample to your lab appointment.

What to Expect Before the Test

No special preparation is needed, but drink plenty of water to support kidney function. Avoid certain medications that may affect kidney function unless instructed otherwise.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low or high ratios may indicate kidney disease, fluid imbalance, or other health issues. This test helps diagnose or monitor chronic kidney disease, kidney stones, or conditions affecting blood flow to the kidneys.

Short name

Urine Creatinine Clearance

Frequently asked questions

How long does the urine collection last?
The urine collection period is exactly 24 hours, from one morning to the next morning. You’ll need to keep track of all urine output during this time.
Can I take my usual medications during urine collection?
Yes, but always check with your doctor or lab technician first. Some medications may affect kidney function or test results, so they may need to adjust your treatment plan if needed.
What if I miss a urine sample or have an accident?
If you miss a sample, start collecting again immediately. If you have an accident, discard the urine and continue collecting from that point. Notify your lab or doctor right away to avoid affecting 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