Lab result explainedUrinalysisLast updated November 10, 2026

Squamous epithelial cells in urine: what rare, few, moderate and many mean

Squamous epithelial cells in urine (Squamous epithelial cells) · Urinalysis (microscopy) · reported in Reported as none, rare, few, moderate or many, or as a count per high-power field (HPF) or low-power field (LPF)

Squamous epithelial cells are the large, flat cells that line the skin, the outer part of the urethra and, in women, the vagina. They are shed constantly, and a few are washed into almost every urine sample as it leaves the body, so seeing "rare" or "few" squamous epithelial cells on a urinalysis is normal and is not a sign of disease. Most laboratories call up to about 5 per high-power field (or up to 15 to 20 per low-power field) normal, with results reported in words (none, rare, few, moderate, many) or as a count.

A result of "moderate" or "many" squamous epithelial cells almost always means one thing: the sample picked up skin or vaginal secretions on the way out, in other words it was not a clean midstream catch. That matters less for the cells themselves than for everything else on the report. A contaminated sample can also carry bacteria, white blood cells and mucus from the skin or vagina, so a positive leukocyte esterase or a mixed-growth culture in a sample with many squamous cells may not reflect what is happening in your bladder, and the usual advice is to repeat the test with careful technique rather than to treat.

Squamous cells are one of three kinds of epithelial cell that can appear in urine, and the lab names them separately because they mean different things. Transitional (urothelial) cells line the bladder and ureters and a few are normal. Renal tubular epithelial cells come from inside the kidney and more than a couple per high-power field suggest tubular injury, such as acute tubular necrosis or interstitial nephritis. If your report simply says "epithelial cells" without a type, it almost always means squamous.

Squamous epithelial cells at a glance

What they are: flat cells shed from the skin around the urethra, the lower urethra and the vagina; they wash into urine as it is passed, not from the kidneys or bladder.
Normal: none to few. Most labs call 0–5 per high-power field (HPF), or up to 15–20 per low-power field (LPF), normal; women and uncircumcised men have more. Labs differ.
Moderate or many squamous cells: the sample was contaminated with skin or vaginal cells; it does not indicate infection or kidney disease, but it makes the bacteria, white-cell and culture results on the same sample less reliable.
Squamous cells studded with bacteria (clue cells) point to bacterial vaginosis; they are a vaginal finding, not a urinary one.
The cells that matter are different: renal tubular epithelial cells (more than about 2 per HPF suggests kidney tubule injury) and atypical or malignant cells on cytology.
Next step: if other results were abnormal, repeat with a careful midstream clean catch (or a catheter sample if needed); if the rest of the report was normal, nothing more is needed.

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What Squamous epithelial cells measures

Urine microscopy is done on the sediment that collects after a few milliliters of urine are spun in a centrifuge. The technologist or an automated analyzer scans the sediment under low power (10x objective) to count casts and gauge the overall picture, then under high power (40x) to count cells. Squamous epithelial cells are the easiest cells to recognize: very large (30 to 60 micrometers, roughly five times the size of a red cell), flat and polygonal with abundant cytoplasm, a small central nucleus and often folded or rolled edges. Automated systems flag them by size and shape and a technologist confirms when counts are high.

Because they are so distinctive, squamous cells are used as a marker of how the sample was collected rather than of disease. The outer third of the urethra in men, the whole urethra in women and the vaginal wall are all lined by squamous epithelium, so the first few milliliters of urine wash these cells along; a midstream sample, taken after the first part of the stream has cleared the urethra, contains far fewer. Laboratories commonly report none, rare (roughly 0 to 2 per field), few (roughly 3 to 5), moderate (roughly 6 to 20) and many (more than 20), though the exact bands and whether they are per high- or low-power field vary from lab to lab.

Many microbiology labs use squamous cell counts to decide whether a urine culture is worth doing: a specimen with more than 15 to 20 squamous cells per low-power field is often labeled contaminated and a recollection requested, because the culture will tend to grow a mixture of skin and vaginal organisms. Research has qualified this rule: in a large emergency-department study, squamous cell counts predicted culture contamination only weakly, but samples with many squamous cells did make the dipstick and white-cell results less accurate for detecting a true infection. So the count is best read as a reliability flag for the rest of the report.

Normal range for Squamous epithelial cells

Reference ranges vary between labs and by age, sex and pregnancy. Use the range printed on your own report.

Group	Typical range (Reported as none, rare, few, moderate or many, or as a count per high-power field (HPF) or low-power field (LPF))	Notes
None seen	Normal	Typical of a well-collected midstream sample or a catheter specimen.
Rare	About 0–2 per HPF; normal	Expected in most samples, especially from women. No action.
Few	About 3–5 per HPF (up to 15–20 per LPF); normal	The upper end of most labs' normal range; minor skin or vaginal contact during collection.
Moderate	About 6–20 per HPF; likely contamination	Bacteria, white cells and mucus on the same report are less reliable. Repeat with a clean catch if those were abnormal.
Many	More than 20 per HPF (or more than 15–20 per LPF); contaminated sample	Culture labs often reject these or report mixed growth; recollection is the usual advice.
Clue cells	Squamous cells coated with bacteria so their edges look fuzzy	A sign of bacterial vaginosis in the vaginal secretions that reached the sample, not of a urinary infection.
Transitional (urothelial) cells	Few per HPF is normal	From the bladder and ureters; more after catheterization or with bladder irritation. Clumps or atypical forms are referred for cytology.
Renal tubular epithelial cells	0–1 per HPF normal; more than about 2 per HPF abnormal	From inside the kidney; raised counts suggest acute tubular necrosis, interstitial nephritis, glomerular disease or viral kidney injury.

Moderate or many squamous epithelial cells

A high count of squamous epithelial cells means the urine picked up cells from the skin around the urethra or from the vagina on its way into the cup. It is a comment on how the sample was collected, not on your kidneys or bladder, and by itself it does not indicate infection, inflammation or cancer. It is extremely common: in surveys of hospital laboratories, roughly 15 to 30 percent of outpatient urine samples are judged contaminated, and the proportion is higher in women, in people with obesity or limited mobility, in uncircumcised men and in infants whose urine is collected with an adhesive bag.

The reason clinicians care is that contamination muddies the rest of the report. Skin and vaginal secretions contain bacteria and white blood cells of their own, so a sample with many squamous cells can show bacteria, a positive leukocyte esterase, even a small or moderate white-cell count, without any infection in the bladder. If a culture is sent from such a sample it tends to grow two or three organisms at low counts ("mixed flora" or "mixed growth"), which cannot be interpreted. Treating a contaminated sample as a urinary tract infection leads to unnecessary antibiotics, and missing a real infection because the sample is dismissed as contaminated is the opposite error, which is why a repeat sample is the standard response when symptoms are present.

Two patterns deserve a second look. Clue cells, squamous cells covered in a stippled coat of bacteria, indicate bacterial vaginosis in the vaginal fluid that reached the sample; the treatment, if any, is for the vagina, not the urinary tract. Very rarely, abnormal squamous cells with large irregular nuclei are seen, usually by a pathologist on urine cytology rather than on routine urinalysis; these can reflect squamous metaplasia or, in people with long-term catheters, chronic bladder infection or schistosomiasis, squamous cell carcinoma of the bladder, which accounts for only a few percent of bladder cancers in the United States.

Common causes

Not a midstream clean catch
The first part of the stream flushes the urethra and carries the most squamous cells; collecting the whole stream, or the first part, raises the count. Starting the stream, then catching the middle portion, is the single biggest factor.
Vaginal secretions
The vaginal lining is squamous epithelium and sheds heavily, especially mid-cycle, during pregnancy, with vaginitis or discharge, and after sex. Women's samples routinely contain more squamous cells than men's for this reason.
Menstruation
Menstrual flow adds squamous cells, red cells and blood to a urine sample; a urinalysis is ideally postponed or done with a catheter during a period.
Skin contact and incomplete separation of the labia or foreskin
Urine running over the labia, perineum or inner foreskin collects skin cells; uncircumcised men and anyone with limited mobility or obesity have higher counts.
Bag specimens in infants and toddlers
Adhesive collection bags sit against the skin and produce contaminated samples in the majority of cases; catheter or suprapubic samples are used when the result matters.
Bacterial vaginosis (clue cells)
Overgrowth of Gardnerella and other anaerobes coats vaginal squamous cells with bacteria, producing the characteristic clue cells; often with a thin gray discharge and a fishy odor.
Vaginal atrophy after menopause and estrogen changes
Thinning vaginal tissue sheds parabasal and squamous cells more readily and is more easily irritated; contamination of samples is more frequent after menopause.
Urethritis or vaginitis
Inflammation from chlamydia, gonorrhea, trichomonas or yeast increases shedding from the urethral and vaginal lining and adds white cells, which can mimic a urinary infection.
Squamous metaplasia or, rarely, squamous cell carcinoma of the bladder
Chronic irritation from long-term catheters, repeated infections, stones or schistosomiasis can change the bladder lining; atypical squamous cells on cytology prompt cystoscopy. This is rare and is not suggested by ordinary squamous cells on urinalysis.

Symptoms that can go with it

None; squamous epithelial cells cause no symptoms and are usually an incidental finding
Vaginal discharge, itching or odor if vaginitis or bacterial vaginosis is the source
Burning, urgency or frequency that persists after a contaminated sample has been repeated, which suggests a genuine urinary or urethral infection
Vaginal dryness or irritation after menopause
Blood in the urine, pelvic pain or difficulty passing urine with a long-term catheter, which warrants review for bladder irritation or, rarely, tumor
Fever, flank pain or nausea, which point to the kidney and need a proper sample and treatment regardless of contamination

Read it alongside

Leukocyte esterase and white blood cells — a positive result with many squamous cells may be contamination; a positive result on a clean repeat means true pyuria.
Nitrite — positive nitrite is much less affected by contamination and supports a real bacterial infection even in a contaminated sample.
Bacteria on microscopy and urine culture — mixed growth of two or more organisms at low counts is the hallmark of contamination; a single organism above 100,000 colony-forming units/mL is infection.
Red blood cells — blood with many squamous cells during a period is contamination; blood on a clean repeat needs its own work-up.
Renal tubular epithelial cells and casts — the epithelial cells that actually indicate kidney injury; check which type the report names.
Mucus threads — common alongside squamous cells from the same source and equally benign.
Vaginal swab or wet mount — if clue cells, yeast or trichomonas are seen, the problem is vaginal and is tested directly.
Urine cytology — ordered when atypical cells of any type are reported or when there is unexplained blood in the urine.

What usually happens next

If everything else on the urinalysis was normal, a moderate or many squamous cell count needs no follow-up; it simply describes the collection.
If leukocytes, bacteria or blood were also flagged and you have symptoms, your clinician will usually repeat the test with a careful midstream clean catch, or a catheter sample if a clean sample is difficult, before deciding on treatment.
If the culture reported mixed growth or was rejected for contamination, a recollection is standard; a single organism at high count on a clean sample is what confirms infection.
Clue cells or a vaginal discharge lead to a vaginal swab or wet mount, and treatment is directed at the vagina rather than the urinary tract.
Atypical squamous or transitional cells, or persistent blood with a long-term catheter, lead to urine cytology and possibly cystoscopy.
Ask: were the other results abnormal, was the sample a clean catch, and does the report distinguish squamous from renal tubular cells?

Diet, lifestyle and natural levers with evidence

What can move Squamous epithelial cells once the cause is known. Nothing here replaces finding the cause.

Collect a true midstream sample

Moderate evidence

Nothing about diet or supplements changes squamous cell counts; collection technique is what matters. Spread the labia or retract the foreskin, start the stream into the toilet, then catch the middle portion without stopping the flow, and avoid touching the inside of the cup. Studies comparing techniques show that midstream collection, rather than the antiseptic wipe itself, is the step that lowers contamination: in a trial of 242 women, cleansing before a midstream sample made no measurable difference to contamination (about 30 percent either way), while first-void and whole-stream samples are consistently worse. Laboratory surveys put overall contamination at roughly 15 percent of samples, lower in labs that give patients written instructions.

Time the sample well

Preliminary evidence

Avoid testing during a period or within a day of sex, when vaginal shedding and secretions are highest, and give the sample before using any vaginal cream or lubricant. A first-morning sample is more concentrated and better for most other urinalysis results, but any time of day is fine for squamous cells as long as the catch is midstream. If a clean sample is repeatedly impossible, for example with heavy discharge or limited mobility, a catheter sample avoids the problem entirely.

Lactobacillus probiotics if clue cells and recurrent bacterial vaginosis are the source

Moderate evidence

Clue cells are a vaginal finding, and the lever is vaginal flora. In a randomized trial of 228 women treated for bacterial vaginosis, a vaginal Lactobacillus crispatus product (LACTIN-V) reduced recurrence at 12 weeks to 30 percent versus 45 percent with placebo. Oral and vaginal lactobacillus products in meta-analyses modestly reduce recurrence after standard treatment; they do not replace treatment of the acute episode.

See a clinician for a diagnosis first; discharge with itching, pelvic pain or fever has other causes, and sexually transmitted infections need specific tests.

When to see a clinician promptly

Burning, urgency, frequency or lower-abdominal pain that continue after a contaminated sample, so that a proper sample can be taken and infection confirmed or excluded.
Fever, chills, flank pain, vomiting or feeling very unwell with urinary symptoms: a possible kidney infection that should not wait for a repeat sample.
Vaginal discharge with pelvic pain, fever or bleeding between periods, or any discharge in pregnancy.
Visible blood in the urine, or blood on repeated clean samples, which needs its own investigation regardless of squamous cells.
Atypical or malignant cells reported on urine cytology, or urinary symptoms with a long-term catheter.
A urinalysis in a young child that shows cells, bacteria or white cells from a bag sample when the child is feverish; a catheter sample is needed to decide treatment.

Frequently asked questions

What does it mean if squamous epithelial cells are in my urine?

Almost always that a few cells from the skin around the urethra or from the vagina washed into the sample as you passed it. Rare or few squamous cells (up to about 5 per high-power field) is a normal finding. Moderate or many means the sample was contaminated during collection; it does not mean infection or kidney disease, but it makes the rest of the report less reliable.

What is a normal amount of squamous epithelial cells in urine?

Most laboratories consider none, rare or few normal, which usually corresponds to 0 to 5 per high-power field or up to about 15 to 20 per low-power field. Labs use different cut-offs and some report only in words. Women typically have more than men because the vagina sheds squamous cells, and uncircumcised men have more than circumcised men.

Does "few squamous epithelial cells" mean I have a UTI?

No. Squamous cells are not a sign of infection in any amount. A urinary tract infection is suggested by white blood cells, a positive nitrite or leukocyte esterase, bacteria on a clean sample and symptoms, and is confirmed by a culture growing one organism at a high count. If those were normal, a few squamous cells need no action.

What do moderate or many squamous epithelial cells mean?

They mean the sample picked up a lot of skin or vaginal material, usually because it was not a midstream catch, was taken during a period, or there was vaginal discharge. The cells themselves are harmless. If the same report also flagged bacteria, white cells or blood, those results may be contamination, and a repeat with careful technique, or a catheter sample, is the usual next step.

What is the difference between squamous, transitional and renal epithelial cells?

They come from different places. Squamous cells line the skin, lower urethra and vagina and are a contamination marker. Transitional (urothelial) cells line the bladder and ureters; a few are normal and more appear after catheterization or with bladder irritation. Renal tubular epithelial cells come from inside the kidney, and more than about 2 per high-power field suggests tubular injury such as acute tubular necrosis or interstitial nephritis. Only the last type points to kidney disease.

Can squamous epithelial cells in urine mean cancer?

Ordinary squamous cells on a urinalysis do not. Squamous cell carcinoma of the bladder is rare in the United States (a few percent of bladder cancers), usually occurs with long-term catheters, chronic infection, stones or schistosomiasis, and is suspected from blood in the urine and abnormal cells on cytology, not from a count on a routine urinalysis. If a report says atypical or malignant cells, that is a different finding and leads to cytology and cystoscopy.

What are clue cells in urine?

Clue cells are vaginal squamous cells coated with so many bacteria that their edges look fuzzy or stippled under the microscope. They indicate bacterial vaginosis in the vaginal secretions that reached the urine sample. They are not a urinary tract infection; a vaginal swab confirms the diagnosis and treatment, if needed, is directed at the vagina.

How do I give a clean-catch urine sample?

Wash your hands, open the sterile cup without touching the inside, separate the labia or pull back the foreskin, start urinating into the toilet, then without stopping move the cup into the stream to collect 1 to 2 ounces (30 to 60 mL), finish in the toilet and cap the cup. Avoid testing during a period if possible. Antiseptic wipes are often provided but studies show the midstream step matters more than the wipe.

References

Urinalysis. MedlinePlus, US National Library of Medicine (2023)View source
Clean catch urine sample. MedlinePlus Medical Encyclopedia, US National Library of Medicine (2023)View source
Urinalysis. Mayo Clinic (2023)View source
Simerville JA, Maxted WC, Pahira JJ. Urinalysis: a comprehensive review. American Family Physician (2005)
Urinalysis. Merck Manual Professional Version (2024)
Lifshitz E, Kramer L. Outpatient urine culture: does collection technique matter?. Archives of Internal Medicine (2000)
Bekeris LG, Jones BA, Walsh MK, Wagar EA. Urine culture contamination: a College of American Pathologists Q-Probes study of 127 laboratories. Archives of Pathology and Laboratory Medicine (2008)
Mohr NM, Harland KK, Crabb V, et al.. Urinary squamous epithelial cells do not accurately predict urine culture contamination, but may predict urinalysis performance in predicting bacteriuria. Academic Emergency Medicine (2016)
Holm A, Aabenhus R. Urine sampling techniques in symptomatic primary-care patients: a diagnostic accuracy review. BMC Family Practice (2016)
Cavanaugh C, Perazella MA. Urine sediment examination in the diagnosis and management of kidney disease: Core Curriculum 2019. American Journal of Kidney Diseases (2019)
Cohen CR, Wierzbicki MR, French AL, et al.. Randomized trial of Lactin-V to prevent recurrence of bacterial vaginosis. New England Journal of Medicine (2020)
Bacterial vaginosis. Centers for Disease Control and Prevention (2024)

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