leukocyturi

Leukocyturi, also known as leukocyturia or pyuria, is the presence of white blood cells in urine. It is typically detected during urinalysis and may indicate inflammation or infection anywhere along the urinary tract. It can be microscopic, where white blood cells are seen under a microscope, or gross, when urine appears pus-like.

Common causes include urinary tract infections such as cystitis or pyelonephritis, urethritis, and kidney or bladder stones. Other contributing factors are urinary tract obstruction, catheterization, and inflammatory or autoimmune conditions such as interstitial nephritis. Sexually transmitted infections (for example, Chlamydia or Gonorrhea) can also cause leukocyturia. In some cases leukocytes appear in urine without a bacterial infection, a situation called sterile pyuria, which may be due to prior antibiotic use, fastidious organisms, tuberculosis, or lower urinary tract inflammation.

Diagnosis relies on urinalysis with microscopic examination, supported by the leukocyte esterase test and urine culture if infection is suspected. If sterile pyuria is found, further testing for specific pathogens and imaging to assess obstruction or kidney involvement may be indicated. Proper urine collection (clean-catch or catheterized samples) helps reduce contamination.

Management depends on the underlying cause. Most UTIs or inflammations require targeted treatment with appropriate antibiotics and supportive care. In cases of sterile pyuria or noninfectious causes, management focuses on addressing the underlying condition and addressing risk factors. Early evaluation is especially important in pregnant individuals, children, the elderly, or those with fever or flank pain.