Leukocyte Esterase in Urine
This test measures a chemical produced by white blood cells when they break down, which can indicate inflammation or infection in your urinary tract.
["A positive result may signal urinary tract issues needing further evaluation."]
Key facts at a glance
- LOINC
- 105103-6
- Short code
- Leukocyte esterase Ur Ql
- Synonyms
- Leukocyte esterase Ur Ql
- 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
- 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
What Is Leukocyte Esterase?
Leukocyte esterase is an enzyme released by neutrophils (a type of white blood cell) when they respond to infection or irritation. In urine, its presence suggests inflammation or infection in the urinary tract, such as a urinary tract infection (UTI).
Why Might This Test Be Ordered?
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 can also be part of a routine check for suspected urinary tract issues.
How Is the Test Performed?
A small urine sample is collected, typically during urination. The sample is then tested for the presence of leukocyte esterase using a dipstick method, which detects the enzyme’s activity. Results are usually available within minutes.
What Do Results Mean?
A positive result (indicating leukocyte esterase presence) suggests inflammation or infection in the urinary tract. A negative result means no detectable enzyme, but further testing may still be needed if symptoms persist.
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.
Leukocyte esterase in urine is a marker for neutrophil activity, often linked to urinary tract infections (UTIs), interstitial cystitis, or other inflammatory conditions. While not definitive, it prompts further evaluation, such as urine culture or imaging, to identify the underlying cause.
Short name
Leukocyte Esterase (Urine)
Frequently asked questions
What causes a positive leukocyte esterase test?
How soon can I expect results?
Can lifestyle changes affect this test?
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