1, isolated kidney function well, usually difficult to detect. It is often found that one kidney is absent when B-type ultrasound or CT examination of both kidneys is performed for some reason. 2.The triangle is asymmetrical during cystoscopy, and the ureteral orifice is absent on one side. 3.Urogram and intravenous urography show no renal shadow or no shadow on one side, and compensatory enlargement of the contralateral kidney. It should be noted that other causes of renal failure should be excluded, such as advanced renal tuberculosis and renal hypoplasia. 4, retroperitoneal gas injection angiography, B-type ultrasound and CT examination show no kidney on one side. It should be differentiated from the symptoms caused by cerebellar ataxia causing random motor coordination disorder.