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Urine Creatinine-to-Albumin Ratio (Creatinine-to-Albumin Ratio, Urinary)

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

This test measures the ratio of creatinine (a waste product from muscle breakdown) to albumin (a protein) in your urine. It helps assess how well your kidneys are filtering proteins, which can indicate early kidney damage or kidney disease.

Quick summary

["A higher ratio may signal kidney problems, even if kidney function tests appear normal."]

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

Key facts at a glance

LOINC
108568-7
Short code
C trach Ag Msmt Urth
Synonyms
C trach Ag Msmt Urth
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 high blood pressure. It’s also used to monitor kidney health in people with diabetes or high blood pressure, as these conditions can damage kidneys over time.

What to Expect Before the Test

No special preparation is needed. You’ll provide a urine sample in the morning, often collected over a 24-hour period (though some labs may use a single random sample). Avoid excessive protein intake or certain medications that could affect results.

How the Test Works

A small amount of urine is collected and analyzed to measure both creatinine and albumin levels. The test calculates their ratio to identify if protein is leaking into urine, which can indicate kidney damage.

What the Results Mean

Results are typically reported as a ratio (e.g., 20 mg/g creatinine). Higher values may suggest kidney issues, but your doctor will interpret results in the context of your overall health and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine C:Alb Ratio

Frequently asked questions

What Does a High Ratio Indicate?
A higher urine creatinine-to-albumin ratio may mean your kidneys are losing protein through urine, which can happen with conditions like diabetic nephropathy, glomerulonephritis, or early kidney disease. It’s a sensitive marker for kidney damage before kidney function declines.
What Does a Low Ratio Indicate?
A low ratio usually means your kidneys are filtering proteins normally. However, a persistently low ratio alone doesn’t rule out kidney issues—your doctor will consider other factors, such as blood pressure, diabetes control, or family history.
Does This Test Replace Other Kidney Tests?
No, this test is often used alongside other kidney function tests (like blood creatinine or GFR) to get a full picture. It’s particularly useful for detecting early kidney problems that might not show up on standard blood tests.
  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