What are the differences between renal pelvis separation and hydronephrosis?

The difference between renal pelvis separation and hydronephrosis is not big. Generally, it is two different descriptions of hydronephrosis or effusion in the kidney. When there is hydronephrosis in the kidney, the patient may show backache and lumbago. At this time, the change of renal pelvis is generally observed by urinary color Doppler ultrasound or urinary CT. When color Doppler ultrasound is done, renal pelvis separation can be observed. Therefore, renal pelvis separation also represents hydronephrosis or effusion. When showing hydronephrosis, it is necessary to actively look for the cause of hydronephrosis. Clinically, the most common cause of hydronephrosis is ureteral stones. Due to the stones stuck in the ureter, urine produced by the kidneys cannot be discharged in time, which will cause hydronephrosis. After examination, separation of renal pelvis can be observed.