Leukocyte esterase in urine (qualitative)
This test detects the presence of leukocyte esterase, an enzyme found in white blood cells. It helps identify potential urinary tract infections (UTIs) by indicating inflammation or infection in the urinary system.
["A positive result may signal a UTI or other urinary tract issues needing further evaluation."]
Key facts at a glance
- LOINC
- 5799-2
- Short code
- Leukocyte esterase Ur Ql Strip
- Synonyms
- Leukocyte esterase Ur Ql Strip
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 4
- Ref high
- 10
- Critical range
- — – 100 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- test-strip
- 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 Is This Test Done?
Your healthcare provider may order this test if you have symptoms like frequent urination, pain or burning during urination, cloudy or strong-smelling urine, or fever. It’s also used as part of a general health check or to monitor conditions like kidney stones or urinary tract infections.
How Is the Test Performed?
A small urine sample is collected, typically during a midstream clean-catch urine test. The sample is then tested for leukocyte esterase using a dipstick method that changes color if the enzyme is present.
What Do the Results Mean?
A positive result (color change) suggests inflammation or infection in the urinary tract, which may require antibiotics or other treatment. A negative result means no detectable enzyme, but further testing may still be needed to rule out other conditions.
What Are Possible Causes?
Positive results can occur with urinary tract infections (UTIs), kidney infections, or other inflammatory conditions of the urinary system. False positives may rarely occur with certain medications or other urinary abnormalities.
Reference range
NCBI: WBC 4000-10000/mm³N/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Leukocyte esterase in urine is a key marker for diagnosing urinary tract infections (UTIs) and related inflammatory conditions. While not definitive on its own, it strongly suggests the need for additional testing, such as a urine culture, to guide treatment decisions. Early detection can help prevent complications like kidney damage or chronic infections.
Short name
Urine Leukocyte Esterase Test
Frequently asked questions
What does a positive result mean for my health?
Can I take anything to prepare for this test?
Will this test show all types of urinary tract infections?
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 17, 2026. · Read our editorial policy