Urine aberrant red blood cells are caused by nephritis, here nephritis includes primary nephritis and secondary nephritis. Patients with nephritis will find red blood cells in the urine routine, which is called hematuria. The appearance of such red blood cells is due to the damage of the filtration membrane of the kidneys, and the red blood cells are formed from the blood into the urine. But the red blood cells will be squeezed and deformed in the process of filtration, it leads to the red blood cells become deformed. Other causes of hematuria, such as kidney stones, urinary tract infections, tumors in the kidneys, and blood system diseases, etc., the red blood cells in the urine are normal. Therefore, by observing whether the red blood cells in the urine are deformed or not, it can be inferred whether the formation of hematuria is related to nephritis or not, which is called urinary erythrocyte profile in medicine. If the proportion of malformed red blood cells in urine erythrocyte profile reaches 80% or more, it is called nephrogenic hematuria.