Hematuria Blood in the urine, silent or painless hematuria Normal Abnormal Hematuria is often a sign of problems in the genitourinary tract (i.e., kidneys, bladder, urethra, prostate).  Blood in the Urine can be visible as red or Coca-cola colored (in macroscopic or gross bleeding), or invisible to the naked eye, evident only on Urinalysis under a microscope (i.e., microscopic Hematuria). Causes include: Kidney Stones Urinary Tract Infection Benign prostatic hypertrophy Prostatitis Trauma Viral infection Medications for Bladder Cancer Kidney Cancer Glomerulonephritis Prostrate cancer After strenuous exercise. Regardless, all Hematuria needs to be evaluated by a doctor.  For further information, refer to specific diseases.