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24-Hour Urine Protein-to-Creatinine Ratio (Proteinuria Screening)

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

This test measures the amount of protein and creatinine in your urine over 24 hours to help check for kidney damage or protein loss in urine.

Quick summary

["Assesses kidney function and detects early kidney issues by comparing urine protein levels to creatinine levels."]

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

Key facts at a glance

LOINC
33488-8
Short code
Symptoms 2.5h p Lac PO Patient-Imp
Synonyms
Symptoms 2.5h p Lac PO Patient-Imp
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85610
SNOMED
396252006
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 recommend this test if you have symptoms like swelling, frequent urination, or high blood pressure, or if you’re at risk for kidney problems. It’s also used to monitor conditions like diabetes or hypertension that can affect kidneys over time.

How the Test Works

You’ll collect all your urine for a full 24-hour period in a special container. The lab then measures protein and creatinine levels to calculate the ratio, which helps identify protein loss in urine.

What to Expect Before the Test

No special preparation is needed, but drink plenty of water to help your kidneys work normally. Avoid certain medications (like NSAIDs) that might affect kidney function unless approved by your doctor.

What the Results Mean

Higher-than-normal ratios may signal kidney problems, such as glomerulonephritis or diabetic kidney disease. Lower ratios might indicate dehydration or other conditions. Your doctor will interpret results in the context of your overall health.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: serum

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24h Urine Protein:Creatinine Ratio

Frequently asked questions

What causes elevated protein in urine?
Elevated protein in urine can be caused by kidney diseases (like glomerulonephritis), diabetes, high blood pressure, or certain infections. It may also appear after injury or exercise. Always discuss symptoms with your doctor.
How often should this test be repeated?
Your doctor may repeat this test if you have kidney risk factors, symptoms, or if your results are abnormal. Follow-up depends on your condition and doctor’s recommendations.
Can diet affect urine protein levels?
Yes, high-protein diets or certain foods (like salt) may temporarily affect urine protein levels. Stick to your doctor’s advice on diet while preparing for this test.
  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