What do the red and white blood cells in urine mean? Red blood cells in urine mean that there is a possibility of bleeding in the urinary tract, which may be microscopic hematuria and not visible to the naked eye. In general, conditions such as urinary tract infections, urinary stones or urinary tract tumors may cause an increase in red blood cells. Urological tumors are the most neglected and the most serious type of disease. The white blood cells in urine mainly represent the severity of urinary tract infections. The higher the number of white blood cells in urine, the higher the severity of urinary tract infections.