Leukocytes, or white blood cells, are part of the body’s immune system, defending against infections and foreign invaders. Their detection in urine often signals an underlying condition requiring medical attention.
Interpreting Leukocytes in Urine
Leukocytes in a urine sample indicate an immune response within the urinary tract or kidneys. Detection occurs via urinalysis, using a dipstick test or microscopic analysis. Dipstick tests screen for leukocyte esterase, an enzyme in white blood cells, while microscopic examination allows direct counting.
While 0-5 leukocytes per high-powered field might be normal, significant levels point to inflammation or infection. Detection, especially with nitrites, can suggest a bacterial infection. However, leukocytes can also be present without bacterial infection, known as sterile pyuria, still indicating inflammation or other issues. Their presence requires further evaluation.
Primary Reasons for Their Presence
Urinary tract infections (UTIs) are the most common reason for leukocytes in urine. They occur when bacteria enter the urinary tract, causing inflammation and triggering an immune response. These infections can cause symptoms such as painful or frequent urination, cloudy or foul-smelling urine, and lower abdominal discomfort.
Kidney infections (pyelonephritis) are a more severe UTI, occurring when bacteria travel from the bladder to the kidneys. This elevates leukocyte levels due to the immune response. Kidney stones can also cause leukocytes by irritating the urinary tract lining and potentially creating blockages that increase infection risk.
Non-bacterial inflammation can also cause leukocytes. Conditions like interstitial cystitis, a chronic bladder condition, can cause their presence. Certain sexually transmitted infections (STIs), such as chlamydia and gonorrhea, can trigger an immune response. Some medications, including certain antibiotics, aspirin, corticosteroids, and diuretics, can increase leukocytes as a side effect. Contamination from external genital areas can also introduce leukocytes, leading to false positives.
Next Steps in Medical Care
When leukocytes are detected, a healthcare professional recommends further diagnostic tests. A urine culture is a common test to identify bacteria or fungi, helping determine the most effective antibiotic if an infection is found.
Depending on the suspected cause, imaging studies (ultrasound, CT, MRI) may check for structural problems in the urinary tract, such as kidney stones or obstructions. Blood tests may also assess for systemic infection or inflammation.
Treatment approaches vary based on the underlying diagnosis. Bacterial infections are treated with antibiotics, including nitrofurantoin, trimethoprim-sulfamethoxazole, and fosfomycin. For conditions like kidney stones, treatment may involve pain management or procedures to remove the stones. Addressing non-infectious inflammation might involve other medications or lifestyle adjustments.
It is important to consult a healthcare provider for an accurate diagnosis and personalized treatment plan, rather than attempting self-diagnosis or self-treatment.