Leukocyte esterase in urine (qualitative)
This test detects the presence of leukocyte esterase, an enzyme found in white blood cells, in your urine. It helps identify if there may be an infection or inflammation in your urinary tract.
["The test can signal possible urinary tract infections or inflammation."]
Key facts at a glance
- LOINC
- 27297-1
- Short code
- Leukocyte esterase Ur-aCnc
- Synonyms
- Leukocyte esterase Ur-aCnc
- 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
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 can also be used as part of a general health check or to monitor conditions like urinary tract infections (UTIs).
What Does a Positive Result Mean?
A positive result (detecting leukocyte esterase) suggests there may be white blood cells in your urine, which could indicate an infection or inflammation. However, a positive result alone does not confirm a UTI—additional tests may be needed to diagnose the cause.
What Does a Negative Result Mean?
A negative result means no leukocyte esterase was detected in your urine, which typically suggests no active white blood cell presence. However, this does not rule out all possible causes of urinary symptoms, so further evaluation may still be needed.
How Is the Test Performed?
This is a simple urine test. You will likely provide a midstream urine sample or use a urine collection kit. A test strip is dipped into the urine, and the strip changes color if leukocyte esterase is present. The result is usually available within minutes.
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
Urine Leukocyte Esterase Test
Frequently asked questions
Leukocyte esterase in urine is commonly associated with urinary tract infections (UTIs), interstitial cystitis, or other inflammatory conditions of the urinary system. While it is a useful screening tool, it is not definitive for diagnosing UTIs alone. Other tests, such as urine culture or imaging, may be needed for a full evaluation.
Ideally, collect your urine sample within 1–2 hours of urinating to ensure the results are accurate. If you have a timed collection (e.g., 24-hour urine), follow your healthcare provider’s instructions carefully. Avoid using hygiene products or strong perfumes before testing to prevent false results.
Yes, you can take antibiotics if prescribed by your doctor, but inform your healthcare provider before the test. Antibiotics may reduce or eliminate leukocyte esterase in your urine, potentially affecting the test results. If you’re unsure, ask your provider for guidance.
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