Urine White Blood Cells (WBC)
The number of white blood cells seen in a urine sample under a microscope. A few are common. More can be a sign of infection or irritation in the urinary tract.
AI-verified against cited sources. Awaiting expert reviewAlso called WBC/HPF, Pus cellsLOINC 5821-4
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What it is
White blood cells, also called leukocytes, are immune cells. A few show up in most urine samples. In a urinalysis, the lab spins the urine, looks at the sediment under a microscope and counts white cells in a standard field of view, called a high-power field (HPF). Some labs print a number or range such as 0–5. Others use words like few or many. Many white cells in urine is called pyuria.
Why it matters
Extra white cells in urine can be a sign that the urinary tract is inflamed or irritated. A urinary tract infection (UTI) is the most common reason, but not the only one. Your clinician reads this count together with your symptoms, the dipstick leukocyte esterase and nitrite results, and sometimes a urine culture.
If it’s high
A count above your lab's range means more white cells than usual were in the sample. It is most often linked to a urinary tract infection. Contamination from the genital area is also common, and so are other kinds of irritation. If a culture finds no bacteria, the finding is called sterile pyuria, which has its own list of possible causes, and your clinician can sort through them.
Common causes
- Urinary tract infection of the bladder or kidney
- Contamination from vaginal or genital secretions during collection (many squamous cells on the same report is a clue)
- Urethritis, including some sexually transmitted infections
- Kidney stones
- A catheter, stent or other foreign body in the urinary tract
- Exercise
- Less common: kidney inflammation (glomerulonephritis), tuberculosis, bladder tumors, viral infections, and some medicines, including corticosteroids and cyclophosphamide
What can help
- Collect a clean-catch, midstream sample and get it to the lab promptly
- Tell your clinician about symptoms such as burning, urgency, fever or side pain, and about any medicines or recent procedures
- Ask whether a urine culture or a repeat sample would help sort out the cause
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
For adults: 0–5 /HPF. Source: Quest Diagnostics, Labcorp, American Family Physician, Cureus (urinalysis table with the treating hospital's reference intervals), Journal of Medical Case Reports (urinalysis table with the treating hospital's reference intervals).
What can affect your result
- How clean the sample was: genital secretions and menstrual blood add white cells
- Sex: AAFP says men normally have fewer white cells in their urine than women
- Time and storage: white cells break down in dilute, alkaline or unrefrigerated urine, so a delay can lower the count
- Exercise
- How your lab counts: per high-power field under a microscope, per microliter on an automated analyzer, or in words. The numbers are not interchangeable
- Genital secretions or menstrual blood in the sample add white cells.
- A sample that sits unrefrigerated, or is dilute or alkaline, can lose white cells to breakdown, so the count reads low.
- Exercise can raise the count.
Reflects the day of the sample. It can change within days as irritation or infection starts or settles.
When to talk to a clinician
See a clinician soon if you have burning with urination, needing to go often, fever, chills, back or side pain, or blood in your urine, whatever this result says. Get urgent care for a high fever with shaking chills, severe back or side pain, vomiting, or confusion.
Questions you could ask
- How do the white cell count, leukocyte esterase and nitrite results fit together for me?
- Could this be from the way the sample was collected, or do we need a repeat?
- Do we need a urine culture to go with this result?
- If the culture shows no bacteria, what else could explain the white cells?
Questions people ask
What does '0–5/HPF' mean on my report?
The lab looked at your spun urine under a microscope and counted the white cells in several standard fields of view. '0–5' means it saw between none and five per field. Many labs treat up to about five as within their range.
Can I have white cells in my urine without an infection?
Yes. Contamination from the genital area, exercise, kidney stones and several other kinds of irritation can all add white cells. If a culture finds no bacteria, clinicians call it sterile pyuria and look at that list of causes.
Why can my dipstick say leukocytes are positive when the microscope shows few cells?
The dipstick looks for an enzyme from white cells, and cells can break down if a sample sits for a while before it is tested. Microscopy counts the cells that are still intact. Your clinician looks at both.
Why does my report show white cells per microliter instead of per HPF?
Some labs use automated analyzers that count a measured volume of urine. Those results use different units and different limits than a microscope count per field, and the two don't convert exactly. Use the range printed on your own report.
Show the science and sources
For clinicians and researchers
Urinary leukocytes are mostly neutrophils. Labs count them by microscopy of centrifuged sediment (AAFP 2022: 10 mL spun for five minutes at 1,500 rpm or more) and report per high-power field, or by automated flow cytometry or image analysis, often reported per µL. HPF counts depend on the volume spun, the resuspension volume and the microscope field, so they do not convert reliably to per-µL counts, and this catalog stores only the per-HPF unit. Quest (5463) and Labcorp (003038) both print an interval of 5 or fewer per HPF. AAFP (2005) states that men normally have fewer than 2 and women fewer than 5 WBCs per HPF, and its summary table gives more than 5 WBCs per HPF a sensitivity of 90–96% and a specificity of 47–50% for culture-confirmed UTI. AAFP (2022) calls more than 5 WBCs per HPF consistent with UTI in symptomatic patients. Cells lyse in dilute, alkaline or unrefrigerated urine (Labcorp), so delay under-counts them, while a dipstick leukocyte esterase can still be positive after cells break down. The differential for sterile pyuria includes Ureaplasma urealyticum, urethritis, balanitis, tuberculosis, bladder tumors, viral infections, nephrolithiasis, foreign bodies, exercise, glomerulonephritis, and corticosteroid and cyclophosphamide use (AAFP 2005).
LOINC 5821-4 (primary), 46702-7, 20455-2. Specimen: urine.
Sources
- Urinalysis, Complete (test code 5463), Quest Diagnostics
- Urinalysis, Routine With Microscopic Examination on Positives: sample report (test 003038), Labcorp (2026)
- Office-Based Urinalysis: A Comprehensive Review, American Family Physician (2022)
- Urinalysis: A Comprehensive Review, American Family Physician (2005)
- 003038: Urinalysis, Routine With Microscopic Examination on Positives, Labcorp
- Unraveling the Complexity of Non-typhoidal Salmonella Genitourinary Infection in HIV: A Case Report and Management Strategy, Cureus (urinalysis table with the treating hospital's reference intervals) (2025)
- An Emerging Human Pathogen: Raoultella Planticola, Cureus (urinalysis table with the treating hospital's reference intervals) (2025)
- Unusual Presentation of Bladder Cancer in a Young Male With Significant Tattoo Exposure: A Case Report, Cureus (urinalysis table with the treating hospital's reference intervals) (2024)
- An uncommon case of Chromobacterium violaceum urinary tract infection in a tertiary hospital in Ghana: a case report, Journal of Medical Case Reports (urinalysis table with the treating hospital's reference intervals) (2026)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.