Finding epithelial cells in urine on a lab report is one of the most common reasons people search for an explanation, and it is also one of the most misunderstood lines on a urinalysis. The phrase covers three completely different kinds of cell, coming from three different places, and they carry three very different meanings. One type usually says something about how the sample was collected. One says something about the bladder and the tubes above it. Only one comes from the kidney itself. In this article you will learn what each type is, how laboratories count and report them, why a high squamous count can make the rest of your report unreliable, how to give a collection that avoids the problem, and which results genuinely deserve a follow-up conversation with your clinician.
What epithelial cells are and why they show up in urine
Epithelium is the lining tissue of the body. It covers skin, and it lines the inside of hollow organs, including every part of the urinary tract from the kidney down to the urethra. These linings renew themselves constantly, so a small number of shed cells washing out in urine is completely normal and expected. Cleveland Clinic states plainly that urine typically contains some epithelial cells from the urinary tract. Their presence, on its own, is not a finding.
What makes the line meaningful is the source. Urine passes through several linings on its way out, and each lining sheds a visually distinct cell. A trained technologist or an automated analyzer can tell them apart by size, shape and nucleus. Because the cells look different, the laboratory can report where they most likely came from, and that origin is what changes the interpretation. This is also why a report that just says a number without naming the type is much less useful than one that specifies squamous, transitional or renal tubular.
Where the microscopic exam fits in a urinalysis
A standard urinalysis has three parts: a visual check of color and clarity, a chemical dipstick, and a microscopic examination of the sediment left after the sample is spun down. Epithelial cells belong to that third part, alongside red cells, white cells, bacteria, crystals and casts. If you want the wider picture of what the microscope sees, consult our urine microscopy results guide. The National Library of Medicine summarizes the same line on its MedlinePlus epithelial cells in urine test page.
The three types of epithelial cells, and why they are not interchangeable
This is the single most important idea on the page, and the one most reports leave out. Grouping all three under one heading makes a harmless collection artifact look like a medical finding, and it can also hide the one type that genuinely points at the kidney.
| Cell type | Where it comes from | What it usually means |
|---|---|---|
| Squamous epithelial cells | Urethra opening, vulva and vagina, skin around the genitals | Almost always a collection issue. The cup picked up surface cells on the way. Many of them suggest the sample is not purely bladder urine, and the rest of the report becomes harder to trust. |
| Transitional epithelial cells (urothelial cells) | Bladder, ureters, renal pelvis, upper urethra | A few are normal. Larger numbers can follow a catheter, a bladder infection, a stone, or a recent procedure. Persistent sheets or abnormal-looking cells are the ones a pathologist looks at more closely. |
| Renal tubular epithelial cells | The tiny tubes inside the kidney that process filtered fluid | The clinically important one. More than an occasional cell suggests the kidney tubules themselves are shedding lining, which is seen in acute kidney injury, certain drug reactions and some kidney diseases. |
Squamous cells: a sampling story, not a disease story
Squamous cells are large, flat and irregular, with a small nucleus, and they are the same kind of cell you would find on a skin swab. The urinary bladder does not make them. When they appear in quantity, the most likely explanation is that the stream washed cells from the genital area into the cup. MedlinePlus describes a high squamous count as a sign the sample contains cells from another part of the body, usually because the area was not cleaned before collection.
Transitional cells: the lining of the plumbing
Transitional cells, also called urothelial cells, are smaller and rounder than squamous cells. They line the stretchy surfaces that have to expand and contract as the bladder fills and empties. A handful in a report is routine. Numbers rise after anything that irritates or scrapes that lining, which is why they are common after catheterization or during an infection. If you are trying to interpret an infection picture, our urine culture results guide explains what the culture adds on top of the microscope.
Renal tubular cells: the ones that point at the kidney
Renal tubular epithelial cells are the smallest of the three, with a large round nucleus that takes up much of the cell. They come from inside the kidney, which is why finding more than the occasional one matters. They often travel with other kidney findings such as casts, so laboratories read them together rather than in isolation. Our urinary casts results guide covers that companion finding, and our urine protein results guide covers the other marker clinicians check alongside it.
How laboratories count and report epithelial cells
There is no single universal scale, which is a large part of why the same result can look alarming on one report and unremarkable on another. Two reporting styles dominate.
The first is semi-quantitative wording: none, rare, few, moderate or many. This is a visual estimate made by scanning several microscope fields. MedlinePlus notes that a normal result is typically reported as few, and that moderate or many can prompt further evaluation. The second style is a count per high-power field, written as HPF, which is what the microscope sees at high magnification. A result like 0-5 per HPF or 6-10 per HPF is describing an average across fields, not a total.
Automated flow cytometry analyzers add a third style, counting particles per microliter. These numbers are not directly comparable with per-field counts, and the thresholds a laboratory uses are specific to its own instrument. That is exactly why a number you find online for one laboratory can be meaningless for yours.
| How your report reads | Usual reading | What typically happens next |
|---|---|---|
| None, rare or few | Expected background shedding | Nothing. The rest of the urinalysis is read normally. |
| Moderate squamous cells | Partial contamination of the sample | Results are read with caution, especially bacteria and white cell counts. |
| Many squamous cells | The sample is not clean bladder urine | A repeat clean-catch collection is often requested, and a culture may be cancelled or flagged as mixed growth. |
| Transitional cells present | Lining of bladder or ureters shedding | Read against symptoms, recent catheter use and other sediment findings. |
| Renal tubular cells present | Kidney tubule lining shedding | Kidney function blood tests and a review of medications are usual next steps. |
Because thresholds differ, the useful question is never only how many, but which type, in what clinical context, and alongside what else. A count of eight squamous cells in someone with no symptoms is a different conversation from a count of eight renal tubular cells in someone whose blood creatinine test results have just risen.
Why many squamous cells make the rest of your report unreliable
This is the practical consequence people rarely hear. Contamination does not just add squamous cells to the list. It also drags in bacteria and white cells from the skin and genital area, and those are precisely the markers used to judge a urinary tract infection. The result is a report that can look like an infection when there is none.
That is why laboratories treat squamous cells as a quality signal for the specimen rather than as a health marker. When counts are high, some laboratories will not proceed to culture at all, or will report mixed growth, meaning several organisms were found in proportions typical of surface flora rather than a single infecting organism. If your report showed that pattern, our bacteria in urine results guide and our white blood cells in urine guide explain how the two are read together.
The same caution applies to the dipstick. A contaminated sample can raise the chemical markers that screen for infection, so a positive strip on a heavily contaminated collection deserves a repeat rather than immediate treatment. Our leukocyte esterase results guide and our urine nitrite results guide cover those two strip markers in detail.
How to give a clean-catch sample
Most squamous contamination is preventable, and the fix costs about thirty seconds. Both MedlinePlus and Mayo Clinic describe essentially the same midstream clean-catch technique.
- Wash your hands before you start, and open the sterile container without touching the inside of the cup or the inside of the lid.
- Clean the area around the urinary opening with the wipe provided. If you have a vulva, spread the labia and wipe from front to back. If you have a penis, wipe the tip.
- Start urinating into the toilet, not the cup. The first part of the stream is the part that flushes the urethra.
- Move the cup into the stream partway through and collect roughly one to two ounces, then finish urinating into the toilet.
- Cap the container without touching the rim, and return it promptly. Mayo Clinic advises delivering the sample within about an hour or refrigerating it.
Two situations deserve a mention to the person collecting your sample. Menstruation can add blood and surface cells to a collection, and vaginal discharge does the same, so it is worth saying so rather than letting the report be misread later.
What transitional and renal tubular findings can point to
Once the collection question is settled, the remaining two types carry real clinical information.
Raised transitional cells
Increased urothelial cells commonly follow mechanical irritation: a catheter, a recent cystoscopy, a stone passing through, or an inflamed bladder lining during infection. Our urinary tract infection symptoms and testing guide covers the infection side, and a stone or a recent procedure explains the mechanical one. Occasionally a pathologist notes cells with unusual shape or nuclei, which triggers a dedicated urine cytology examination rather than a repeat urinalysis.
Raised renal tubular cells
Renal tubular cells appearing in more than trace numbers indicate the kidney tubules are shedding their lining. Recognized contexts include acute kidney injury, injury from certain medications, and some inflammatory kidney conditions. They are usually interpreted together with protein in the urine, casts, and blood tests of kidney function. If a clinician is considering chronic kidney involvement, our chronic kidney disease overview describes how that picture is built.
When a result needs follow-up
Use this as a conversation starter with your clinician, not as a substitute for their judgment.
- Contact your clinician if the report names renal tubular epithelial cells, whatever the count, particularly if a kidney function blood test changed at the same time.
- Ask about repeating the test if the report shows many squamous cells together with bacteria, because the infection signal may belong to the collection rather than to your bladder.
- Seek prompt care for fever, flank or back pain, shaking chills, or vomiting alongside urinary symptoms, since those suggest infection reaching the kidney rather than the bladder. Our kidney infection symptoms guide describes that pattern.
- Raise visible blood in the urine, or an unexplained rise in epithelial cells that persists across two properly collected samples, with your clinician even if you feel well.
- Mention every medication and supplement you take, since some drugs are recognized causes of tubular injury.
Latest scientific advances
Research over the past three years has focused less on what epithelial cells are and more on how much weight laboratories should give them when deciding whether a sample is usable. Three studies stand out for a general reader.
A large 2025 analysis from a Los Angeles County health system compared urinalysis results with the cultures that followed, across roughly 81,000 paired samples. It ranked which parts of the urinalysis best predicted a genuine infection-causing organism. White blood cells were the strongest predictor. Squamous epithelial cells were the weakest by a wide margin, performing close to a coin toss. What this means for you: a squamous count is not a test for infection, and it should not be read as one. Its job is to tell the laboratory how clean the sample was.
A 2025 study from a large hospital in Brazil looked at whether an automated analyzer could use squamous cell counts as a formal quality check on the specimen. It found that samples above a certain squamous threshold were substantially more likely to grow a mixed set of organisms, the pattern that signals contamination rather than infection, and that the useful threshold differed between women and men. What this means for you: laboratories increasingly have an objective, instrument-based way to flag a sample as compromised, which is a good thing. It also confirms that a squamous count that would be unremarkable in one person can be a red flag in another. A cross-sectional study, meaning one that photographs a population at a single moment rather than following it over time, cannot prove cause, and thresholds still need confirming across other laboratories and instruments.
A 2023 study in a Chinese hospital laboratory asked why rapid automated screening for urinary infection produces so many false alarms. The answer was contamination, and among women the false alarms were statistically linked to squamous epithelial cell counts. What this means for you: if your rapid screen suggested infection but your culture came back mixed or negative, a contaminated collection is a common and benign explanation, and a repeat clean-catch sample usually settles it.
Taken together, these findings support a simple practical message. Squamous epithelial cells belong to the quality-control column of your report. Renal tubular cells belong to the clinical column. Reading them the same way is the mistake most worth avoiding.
Glossary
| Term | Definition |
|---|---|
| Epithelium | The lining tissue that covers skin and the inside surfaces of hollow organs, including the whole urinary tract. |
| Squamous epithelial cell | A large flat cell from the skin, vulva, vagina or urethral opening. In urine it usually reflects how the sample was collected. |
| Transitional epithelial cell | Also called a urothelial cell. It lines the bladder, ureters and renal pelvis, surfaces that stretch as urine collects. |
| Renal tubular epithelial cell | A small cell with a large nucleus from the tubules inside the kidney. It is the type with the most direct clinical meaning. |
| High-power field (HPF) | The circle of view the microscope shows at high magnification. Counts are averaged across several such fields. |
| Clean catch | A collection method in which the area is cleaned first and only the middle part of the stream goes into the cup. |
| Contamination | The presence of cells or bacteria from outside the urinary tract in a urine sample, which makes the results harder to interpret. |
| Mixed growth | A culture result showing several organisms in proportions typical of surface flora rather than one infecting organism. |
| Urine sediment | The solid material left after a urine sample is spun in a centrifuge, which is what the microscopic exam examines. |
| Flow cytometry analyzer | An automated instrument that counts urine particles as they pass a detector, reporting results per microliter. |
FAQ
What does few epithelial cells in urine mean?
Few is the wording most laboratories use for a normal, expected amount. The linings of the urinary tract renew themselves continuously, so a small number of shed cells appears in almost every sample. On its own, a result of few does not point to infection, kidney disease or any other condition, and it does not usually prompt a repeat test. Your clinician will still read it alongside the rest of the urinalysis, because the meaning of any single line depends on what the others show.
Is a result of 10 to 12 epithelial cells in urine something to worry about?
It depends far more on which type was counted than on the number itself. If those are squamous cells, the most likely explanation is that the sample picked up surface cells during collection, and a repeat clean-catch sample often returns a much lower count. If the report specifies renal tubular cells, that same number carries much more weight and warrants a conversation with your clinician. Counting scales also vary between laboratories, so compare the result with the reference wording printed on your own report rather than with a number from another source.
What is the normal range of epithelial cells in urine?
There is no single number that applies everywhere. Some laboratories report descriptive categories such as none, rare, few, moderate or many, while others give a count per high-power field, and automated analyzers report particles per microliter. Each system has its own thresholds. In practice, results in the none-to-few range are treated as normal, moderate results prompt cautious interpretation, and many usually leads to a repeat collection when the cells are squamous.
Do epithelial cells in urine mean I have an infection?
Not by themselves. Research comparing urinalysis results with cultures found squamous epithelial cells to be a poor predictor of infection, while white blood cells were the strongest single indicator. A high squamous count actually makes an infection result harder to trust, because contamination can add both bacteria and white cells from outside the urinary tract. Infection is diagnosed from symptoms plus the culture and the other sediment findings, not from an epithelial cell count.
Why are epithelial cells often reported during pregnancy?
Pregnancy brings more frequent urine testing and also more vaginal discharge, and both make contaminated collections more likely. A raised squamous count in this setting usually reflects the sample rather than a problem with the pregnancy or the kidneys. Mentioning any discharge before you collect, and following the clean-catch steps carefully, resolves most of these results. Any result your clinician considers unclear can be checked with a repeat sample.
Are squamous epithelial cells more common in women?
Yes. Anatomy makes it easier for cells from the vulva and vagina to reach the cup during collection, which is why some laboratories apply different contamination thresholds for women and men. Recent laboratory research found the squamous count that signals a compromised sample to be considerably higher in women than in men. This is a difference in collection risk, not a difference in health, and careful clean-catch technique narrows the gap.
Sources
- MedlinePlus, National Library of Medicine — Epithelial Cells in Urine — MedlinePlus Medical Test, reviewed 2024 — medlineplus.gov
- Cleveland Clinic — Urinalysis: What It Is, Purpose, Procedure, Results and Types — Cleveland Clinic Health Library, reviewed 2024 — my.clevelandclinic.org
- Mayo Clinic — Urinalysis — Mayo Clinic Tests and Procedures, 2024 — mayoclinic.org
- Kupferwasser DK, Kang AY, Bolaris M, Huse H, Chen L, Miller L — Diagnostic stewardship cutoffs for urinalysis results prior to performing a urine culture: analysis of data from a healthcare system — Infection Control and Hospital Epidemiology, 2025 — doi.org/10.1017/ice.2025.10265
- Walber GB, Poloni JAT, Rotta LN — Quality indicators for urine sample contamination: can squamous epithelial cells and bacteria count be used to identify properly collected samples? — Clinical Chemistry and Laboratory Medicine, 2025 — doi.org/10.1515/cclm-2024-1199
- Zhang G, Dai Z, Yao Y, Yu X, Gao Y, Liang XM, Chen M — Analysis of factors with low positive predictive value in the diagnosis of urinary tract infection by flow cytometry — World Journal of Urology, 2023 — doi.org/10.1007/s00345-023-04676-6
Further reading
- Review the full sediment picture by reading our urine microscopy results guide.
- Interpret the test that confirms or rules out infection with our urine culture results guide.
- Check the marker that tracks white cells in the urinary tract in our pyuria test results guide.
- Understand the kidney finding often reported alongside tubular cells with our urinary casts results guide.
- Explore how concentration changes every microscopic count by reading our urine specific gravity results guide.
Understand your lab results with BloodSense
An epithelial cell count only makes sense next to the rest of your urinalysis: the white cell count, the bacteria, the protein, the casts and the dipstick markers. BloodSense reads those lines together and explains, in plain language, which finding is about your sample and which is about your body. It helps you understand what your report says and prepare better questions for your appointment; it does not diagnose anything and it does not replace your clinician.
