Guide to WBC in Urine

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

White blood cells in urine are immune cells that typically occur in your blood, but inflammation or infection in the urinary tract can lead to an elevated appearance in urine.

Why It Matters

White blood cells are specialized immune cells that detect and fight infections by targeting bacteria, viruses, and other pathogens. Normally, very few white blood cells should appear in your urine.

When white blood cells are detected in urine (a condition called pyuria), it signals that you may have an infection or inflammation in the urinary tract.

The most common cause of white blood cells in urine is a urinary tract infection (UTI), which can occur in the urethra, bladder, or kidneys. However, it can also be caused by sexually transmitted infections, inflammation from kidney stones, certain medications, or autoimmune conditions. Sometimes, contamination during sample collection (especially in women) can introduce white blood cells from the genital area into the sample.

Associated Symptoms 

WBCs in urine are a laboratory finding rather than a medical condition. Symptoms depend on the underlying issue, such as a UTI, kidney stones, or inflammation. Some people, especially older adults or those with catheters, may have WBCs in urine without symptoms.

Common symptoms that may indicate conditions associated with high levels of WBC in urine:

• Frequent urination: Increased urge to urinate may be due to bladder irritation from infection or inflammation
• Urinary hesitancy: The feeling that you need to urinate but can't
• Burning or pain during urination: Discomfort when passing urine can be caused by irritation of the inflamed urinary tract lining
• Cloudy or strong-smelling urine: Changes in urine appearance or odor may be due to the presence of white blood cells, bacteria, and inflammatory proteins
• Lower abdominal or back pain: Discomfort can result from inflammation in the bladder or kidneys, particularly noticeable in the lower abdomen or flank region
• Feeling of incomplete bladder emptying: Sensation that the bladder isn't fully empty after urination may be due to inflammation-induced bladder irritability
• Blood in urine: Pink, red, or cola-colored urine potentially resulting from damaged blood vessels in the inflamed urinary tract

It's important to understand that many factors can cause these symptoms, and WBC in urine is just one piece of diagnostic information. The presence of symptoms alongside elevated WBC in urine provides context for further investigation, but additional testing is typically needed to determine the underlying cause. Some people with WBC in urine may be completely asymptomatic, particularly in cases of mild inflammation or early infection.

Clinical Ranges

Lab Reference Range: ≤5 /HPF

Lifestyle Factors That Can Impact It

Activities that may affect white blood cells in urine include:

• Hydration levels: Drinking adequate water dilutes urine and helps flush bacteria from the urinary tract, potentially reducing white blood cell counts in those with mild infections.
• Holding urine for extended periods: Regularly delaying urination can allow bacteria to multiply in the bladder, potentially leading to infection.
• Diet: Acidic foods (e.g., coffee and spicy foods) may irritate the bladder for some people with conditions like interstitial cystitis, but this is not a universal trigger. A balanced diet supports overall urinary health.
• Personal hygiene: Poor hygiene practices can introduce bacteria to the urinary tract. Proper wiping technique (front to back), regular cleaning, and wearing breathable underwear can help prevent bacterial growth.
• Sexual activity: Frequent sexual activity can increase the risk of UTIs, especially in women. Urinating before and after sexual activity can help reduce bacterial transfer.

Other Factors That Can Impact It

Medical Conditions

• Urinary tract infections (UTIs). UTIs are among the most common causes of elevated white blood cells in urine.  
• Interstitial cystitis: A chronic condition causing bladder pressure and pain, often with white blood cells present due to inflammation but without infection.  
• Kidney stones: These mineral deposits can scratch and irritate the urinary tract, leading to inflammation and white blood cells in urine.
• Sexually transmitted infections: Conditions like chlamydia and gonorrhea can cause urethritis (inflammation of the urethra) resulting in white blood cells in urine.
• Prostatitis: Inflammation of the prostate in men can cause white blood cells to leak into urine.
• Kidney disease: Various kidney disorders can cause kidney inflammation, releasing white blood cells into the urine.

Medications and Supplements

• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Certain antibiotics
• Vitamin C supplements

Individual Factors

• Age: Older adults have a higher risk of UTIs and may have white blood cells in urine more frequently.
• Sex: Women have a shorter urethra than men, making bacterial entry easier and UTIs more common.
• Pregnancy: Hormonal and anatomical changes can increase UTI risk during pregnancy.
• Catheter use: Indwelling catheters significantly increase the risk of bacteria entering the urinary tract.

Testing Accuracy and Stability

White blood cell testing is generally reliable, but certain factors may affect results.

Factors That Can Affect the Accuracy of Your Test 

• Recent sexual activity
• Dehydration (can concentrate urine and affect cell counts)
• Certain foods and medications (can interfere with chemical dipstick tests)

How It Relates to Other Markers

Other tests can provide insights about health status when they're viewed alongside white blood cell count results. These tests may include:

• Nitrite Test: Detects the presence of bacteria that convert nitrates to nitrites, potentially suggesting a bacterial infection.
• Blood in urine (Hematuria): Often performed alongside white blood cell testing, as both can indicate UTI or other urinary tract issues.  
• Kidney function tests: Measures substances like creatinine and BUN in blood to assess kidney function.
• White blood cell count in the blood: WBC in the urine plus elevated WBC in the blood can be seen in pyelonephritis (advanced urinary tract infection)

What Results May Mean in the Context of Other Markers

• White Blood Cells + Nitrites + Bacteria: This combination may suggest a bacterial urinary tract infection.  
• White Blood Cells + Protein: This may indicate kidney inflammation (nephritis) or early signs of kidney disease, especially if persistent.

Follow-up Considerations

If the level of white blood cells in your urine is high, your provider may make some of the following recommendations. You should always speak to your doctor if you have medical questions or before making medical decisions.

When Re-Testing May Be Appropriate

• If symptoms persist despite treatment
• During pregnancy if you have risk factors for UTIs

Additional Testing Your Doctor May Consider

• Urine culture
• Complete blood count
• Comprehensive metabolic panel
• Imaging studies if structural issues are suspected
• STI testing if sexually transmitted infection is possible
• Cystoscopy for recurrent unexplained white blood cells in urine

When Additional Care May Be Warranted

• Having a fever over 100.4°F
• If you have severe pain in your back near the ribs (flank pain)
• If you see blood in your urine
• If symptoms worsen despite treatment
• If you have recurrent UTIs (3 or more in a year)
• If you have a compromised immune system

Bibliography