Free urinary protein (quantitative)
This test measures the amount of protein found in your urine, which can help detect kidney issues or other conditions affecting protein loss.
["Checking protein in urine helps spot early kidney problems or excessive protein loss."]
Key facts at a glance
- LOINC
- 55900-5
- Short code
- UIFLC
- Synonyms
- BJ Protein Free Ur Ql IFE
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container, no preservative required (preferred); or 24-hour urine container with no preservative for timed collections
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immunofixation
- CPT
- 86335
- SNOMED
- 313364003
- Specimen volume
- 10-50 mL random urine specimen; or complete 24-hour urine collection
- Stability
- Room temperature: 2 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms like swelling, frequent urination, or blood in urine. It can also be used to monitor kidney function, screen for conditions like diabetes or kidney disease, or evaluate protein loss from other causes.
What Does the Result Mean?
Higher-than-normal protein levels in urine may indicate kidney damage, diabetes, or other health problems. Lower levels are usually normal, but results depend on your medical history and symptoms.
How Is the Test Performed?
A small urine sample is collected, often in the morning. The sample is sent to a lab where it is analyzed to measure protein concentration.
What Are Common Causes?
Conditions like kidney disease, diabetes, infections, or certain medications can cause abnormal protein levels. Stress, exercise, or certain foods may also temporarily affect results.
Reference range
Negative (No monoclonal free light chains detected). Healthy individuals may excrete small amounts of polyclonal free light chains. A positive result indicates the presence of monoclonal kappa or lambda free light chains (Bence Jones proteins).N/A
No fasting required. Patient should maintain normal hydration. First morning void or 24-hour urine collection may be preferred for optimal detection of free light chains. Avoid excessive fluid intake immediately before collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test is critical for diagnosing and monitoring kidney-related disorders, such as nephrotic syndrome or glomerulonephritis. Elevated protein in urine can signal kidney strain, while persistently low levels may warrant further investigation for underlying metabolic or systemic conditions.
Frequently asked questions
What does a high protein level in urine mean?
Can diet affect this test?
How often is this test repeated?
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