High squamous epithelial cells in urine almost always mean the sample was contaminated during collection, not that something is wrong with your urinary tract. These cells line the outer surfaces of the vagina, urethra, and surrounding skin, so they easily end up in a urine cup if the area isn’t cleaned beforehand. A normal result is 0 to 2 squamous epithelial cells per high-power field on a microscope slide. When the lab reports “moderate” or “many,” the most common next step is simply collecting a new sample with better technique.
Where These Cells Come From
Squamous epithelial cells are flat, scale-like cells that form the outermost layer of skin and mucous membranes. In the urinary and reproductive systems, they line the urethra, the vulva, and the vaginal walls. They’re the largest type of epithelial cell found in urine and by far the most common, especially in samples from women and people with vaginas. Because these cells sit right at the exit point for urine, they’re easily swept into the stream during collection.
This is different from the other types of epithelial cells a lab might find. Transitional epithelial cells come from deeper in the urinary tract, lining the bladder and ureters, and their presence can point to infections, kidney stones, or bladder inflammation. Renal tubular epithelial cells come from the kidneys themselves, and finding them suggests possible kidney damage or a viral infection affecting the nephrons. Squamous epithelial cells, by contrast, carry no pathological significance on their own. They’re surface cells, and their presence in urine tells the lab more about how the sample was collected than about what’s happening inside your body.
Why Contamination Is the Most Likely Explanation
When you urinate into a cup without first cleaning the surrounding skin, cells from the outer genital area wash into the sample along with the urine. Bacteria from the skin can come along too, which is a bigger problem: a contaminated sample can produce a false-positive result on a urine culture, making it look like you have a urinary tract infection when you don’t. Labs use the squamous cell count as a red flag for this. If they see large numbers of squamous cells under the microscope, they know the sample likely picked up material from the skin surface and the results may not be reliable.
This is why your provider will typically ask you to repeat the test using a proper clean-catch technique rather than immediately treating based on the results.
How to Collect a Clean-Catch Sample
The clean-catch midstream method is designed to keep skin cells and bacteria out of your urine sample. Ideally, collect the sample when urine has been sitting in your bladder for two to three hours so you have a good volume to work with.
If you have a vagina, sit with your legs apart and use two fingers to spread the labia. Wipe the inner folds from front to back with a sterile wipe, then use a second wipe over the urethral opening. Start urinating into the toilet, then move the cup into the stream midway through. Fill it about halfway and finish in the toilet. If you have a penis, clean the head with a sterile wipe (pulling back the foreskin if uncircumcised), let the first portion of urine go into the toilet, then catch the midstream portion in the cup.
The key steps are the initial cleaning and discarding the first bit of urine. That first splash carries the most skin cells and surface bacteria. By catching only the middle of the stream, you get a sample that more accurately reflects what’s actually in your bladder. Screw the lid on without touching the inside of the cup.
When It Might Mean Something Else
In a small number of cases, elevated squamous epithelial cells show up even with good collection technique. This can happen with conditions that cause inflammation or irritation in the lower urinary or reproductive tract. A urinary tract infection affecting the urethra (urethritis) can increase the number of cells shed from the urethral lining. Vaginal yeast infections, which occur when the natural balance of bacteria in the vagina shifts and allows yeast to overgrow, can also lead to higher squamous cell counts.
The difference is context. If your urine also shows white blood cells, bacteria, or nitrites, there may be an actual infection driving the cell shedding. If squamous cells are the only unusual finding, contamination remains the overwhelming favorite explanation. Your provider will look at the full urinalysis picture, not just the epithelial cell line, before deciding whether further testing or treatment is needed.
What Your Lab Report Typically Shows
Most labs report squamous epithelial cells using either a number per high-power field (HPF) or a qualitative scale: few, moderate, or many. Normal is 0 to 2 per HPF. “Few” generally doesn’t raise concerns. “Moderate” or “many” is where labs start flagging the sample as potentially contaminated, and your provider may want a repeat collection before interpreting other results like a urine culture.
If you’ve been asked to resubmit a sample, it doesn’t mean something is wrong. It means the lab couldn’t trust the accuracy of the first one. A clean recollection usually resolves the issue entirely, bringing the squamous cell count back to normal range and giving your provider reliable results to work with.