Leukocyte Esterase Activity (Urinary)
This test measures the presence of an enzyme produced by white blood cells in your urine. It can help detect inflammation or infection in your urinary tract.
["A positive result may signal urinary tract issues needing further evaluation."]
Key facts at a glance
- LOINC
- 110367-0
- Short code
- Leukocyte esterase Msmt Ur
- Synonyms
- Leukocyte esterase Msmt Ur
- 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 This Test Measures
Leukocyte esterase is an enzyme released by neutrophils (a type of white blood cell) when they’re activated by infection or inflammation. When this enzyme appears in urine, it often indicates an infection or irritation in the urinary system, such as a bladder or kidney infection.
Why It Might 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’s also used as part of a general screening for urinary tract issues.
What to Expect Before the Test
No special preparation is needed. You may be asked to collect a midstream urine sample in a clean container, or a sample may be obtained from a catheter if needed. Drink plenty of fluids the day of the test to help flush your system.
What the Results Mean
A positive result (detectable enzyme activity) suggests inflammation or infection in the urinary tract. A negative result means no significant enzyme activity was found, but further testing may still be needed to rule out other conditions.
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.
◆Associated findings1
Short name
Urinary Leukocyte Esterase
Frequently asked questions
What does a positive leukocyte esterase test mean?
Can I drink water before this test?
Does this test replace a urine culture?
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