Pyuria

The presence of pus in the urine, characterized by increased urinary leukocytes, reflecting inflammation or infection of the urinary tract or kidneys.

Causes

• Infectious causes

  • Urinary tract infection (bacterial, viral, fungal, parasitic)

  • Tuberculosis of the urinary tract

  • Sexually transmitted infections: Chlamydia, gonorrhea, trichomoniasis

• Inflammatory causes

  • Urolithiasis

  • Interstitial cystitis

  • Systemic lupus erythematosus

  • Kawasaki disease

  • Adjacent inflammatory processes affecting the urinary tract

• Medication-related causes

  • NSAIDs

  • Proton pump inhibitors (PPIs)

  • Diuretics

• Iatrogenic and structural causes

  • Urinary catheterization

  • Urinary tract instrumentation

  • Urinary obstruction

• Neoplastic and renal causes

  • Renal tumors

  • Polycystic kidney disease

  • Kidney transplant rejection