Upon the analysis of qualitative and quantitative characteristics of hematuria in renal and urinary tract affections it was established that whatever the red blood cell count in the urine, hematuria is primarily glomerular in contrast to nonglomerular in chronic glomerulonephritis and nonglomerular diseases of the kidneys and urinary tracts, respectively. Morphologic studies of urinary red blood cells using phase-contrast microscopy proved a valuable tool for identification of hematuria origin.