Epithelial cells are cells that line the surfaces of your body, including your urinary tract. When these cells appear in a urine sample, it is called epithelial cells in urine. Finding a small number of certain types, especially squamous cells, is normal. But higher numbers or specific types like renal tubular cells may signal an underlying condition that needs attention.
What Are Epithelial Cells In The Urine?
Epithelial cells form a protective layer on the surfaces of your body. This layer is called epithelium. The cells line your skin, blood vessels, and organs. In the urinary tract, they line the kidneys, ureters, bladder, and urethra.
As these cells age or become damaged, they shed into urine. A urinalysis looks for these cells under a microscope. The type and number tell your doctor something about what is happening in your urinary tract.
Not all epithelial cells are the same. Different types come from different parts of the urinary system. This is why your doctor pays attention to which type appears, not just how many.
What Are the Different Types of Epithelial Cells?
There are three main types of epithelial cells found in urine. Each type comes from a different location. Each has a different meaning.
Squamous epithelial cells are the largest type. They come from the urethra and the outer part of the genital area. These are the most common cells found in urine. A few squamous cells are almost always normal. They enter the sample during urination. Large numbers may suggest a contaminated sample rather than a medical problem.
Transitional epithelial cells are round or pear-shaped. They line the bladder, ureters, and part of the kidney called the renal pelvis. Small numbers can be normal. Higher numbers may indicate inflammation or irritation in these areas, such as from a urinary tract infection.
Renal tubular epithelial cells are the smallest type. They come from the tiny tubules inside the kidneys where urine is formed. These cells should not be present in urine. Finding them is never normal. They suggest injury or damage to the kidney tissue itself.
| Cell Type | Source Location | What It Usually Means |
|---|---|---|
| Squamous | Urethra, genital area | Usually normal or sample contamination |
| Transitional | Bladder, ureters, renal pelvis | Small numbers normal; higher numbers may mean irritation |
| Renal tubular | Kidney tubules | Always abnormal; suggests kidney injury |
What Does a High Number of Epithelial Cells Mean?
A high number of epithelial cells on a urinalysis report is not a diagnosis by itself. It is a clue. The meaning depends entirely on which cell type is elevated.
If squamous cells are high, the most common reason is a contaminated sample. This happens when cells from the skin or genital area mix into the urine during collection. A clean catch sample often resolves this. Some labs do not even report squamous cells unless the number is very high for this reason.
If transitional cells are elevated, the cause is often irritation or inflammation. A urinary tract infection is a common trigger. Bladder stones or catheter use can also cause higher numbers. In some cases, medications that irritate the bladder lining may be responsible.
If renal tubular cells are present at all, that is always significant. The number does not need to be high to be concerning. Even a few renal tubular cells suggest the kidney tissue may be injured. Conditions like acute kidney injury, kidney infection, or toxin exposure can cause this finding.
What Can Cause Epithelial Cells in Urine?
The causes range from normal to serious. A few common reasons include:
- Normal shedding. Cells naturally turn over and shed into urine. This is especially true for squamous cells.
- Sample contamination. Poor collection technique brings in vaginal or skin cells. This is the most common cause of high squamous cell counts.
- Urinary tract infection. Inflammation from an infection causes more cells to shed. This usually raises transitional cells.
- Kidney infection. An infection inside the kidney tissue can cause renal tubular cells to appear.
- Kidney injury. Damage from medications, toxins, or reduced blood flow can shed renal tubular cells.
- Bladder irritation. Catheters, stones, or certain drugs can irritate the bladder lining and increase transitional cells.
- Pregnancy. Hormonal changes and increased pressure on the bladder can cause more cells to shed. This is usually not a concern on its own.
Most causes of epithelial cells in urine are not serious. But when renal tubular cells appear, further testing is needed to check kidney function.
How Are Epithelial Cells in Urine Diagnosed?
Epithelial cells are found during a routine urinalysis. A sample of urine is examined under a microscope. The technician counts the number of each cell type seen per high-power field.
Your doctor looks at the full picture. The cell type and number are considered along with other urine findings. Things like white blood cells, red blood cells, bacteria, and protein levels all provide context. Symptoms also matter. Fever, pain with urination, or flank pain change how the results are interpreted.
If renal tubular cells are found, doctors typically order blood tests to check kidney function. These include creatinine and blood urea nitrogen levels. A repeat urine test is common to confirm the finding.
Most clinical laboratories do not report a strict universal normal range for epithelial cells. Reference ranges vary by lab. But a common standard is that squamous cells are considered normal at 0 to 2 per high-power field. Any renal tubular cells are considered abnormal regardless of number.
When Should You See a Doctor?
Epithelial cells in urine are often found by accident during a routine test. If you have no symptoms and only a few squamous cells, no action is needed. This is a normal finding.
You should follow up if your urinalysis shows renal tubular cells or a high number of transitional cells. You should also follow up if you have symptoms along with epithelial cells. These symptoms include:
- Pain or burning when you urinate
- Frequent or urgent need to urinate
- Blood in your urine
- Pain in your lower back or side
- Fever or chills
Your doctor will determine whether the finding is meaningful based on your full health picture. A single abnormal result does not always mean a problem exists. Repeat testing is a standard part of the process.
Can You Prevent Epithelial Cells in Urine?
You cannot prevent normal cell shedding, and you should not try to. This is a natural process. But you can reduce the chance of a contaminated sample. A clean catch urine collection method helps. For women, this means cleaning the genital area and collecting urine midstream. For men, retracting the foreskin before collection helps reduce contamination.
Staying hydrated supports kidney health but does not directly prevent epithelial cells from appearing. No specific diet or supplement has been shown to reduce epithelial cells in urine. When the cells appear due to an infection or kidney issue, treating the underlying condition is what resolves the finding.
What Is the Difference Between Epithelial Cells and Other Cells in Urine?
Urine can contain several types of cells. Each has a different meaning. Epithelial cells are lining cells. White blood cells suggest infection or inflammation. Red blood cells suggest bleeding somewhere in the urinary tract. Bacteria suggest a urinary tract infection if the sample was collected cleanly.
Your lab report will list each cell type separately. Your doctor interprets them together. For example, epithelial cells combined with white blood cells and bacteria strongly suggest a urinary tract infection. Epithelial cells with protein and renal tubular cells point toward a kidney problem.
Understanding which cell type is in your urine and what accompanied it is far more important than knowing the total count alone.
Frequently Asked Questions
Can epithelial cells in urine be a sign of cancer?
In rare cases, abnormal transitional cells can be associated with bladder cancer, but this is not common.
A routine urinalysis alone cannot diagnose cancer — your doctor would need additional tests like cytology or a cystoscopy to investigate further.
How are epithelial cells in urine treated?
Epithelial cells themselves are not treated — the underlying cause is.
If an infection is present, antibiotics resolve it, and the cells clear on their own as the tissue heals.
Can dehydration cause epithelial cells in urine?
Dehydration alone does not typically cause epithelial cells to appear in urine.
However, very concentrated urine can make any cells present look more numerous under the microscope because there is less fluid diluting the sample.
What is a normal range for epithelial cells in urine?
Most labs report 0 to 2 squamous epithelial cells per high-power field as normal.
Any number of renal tubular epithelial cells is considered abnormal and requires follow-up testing.
