Separation of right kidney suggests that the right renal pelvis may have fluid accumulation, or may have renal pelvis cancer. Right renal separation, the full name is right renal pelvis separation, refers to the anterior and posterior diameters of the renal pelvis are larger than 0.7cm, especially larger than 1cm.The most common cause of renal pelvis separation is hydronephrosis, and a small number of patients are due to renal pelvis cancer. Long-term hydronephrosis will lead to renal cortical pressure, renal function reduction and may develop into renal failure. If it is caused by renal cancer, it may cause metastasis and lead to death. Once the separation of renal pelvis is found, the cause should be actively searched and treated from the etiology. If the hydronephrosis is caused by kidney stone, prostate hyperplasia or tumor, it is usually treated by surgery. If the separation of renal pelvis is caused by renal pelvis cancer, surgical treatment needs to be given, and chemotherapy or radiotherapy may need to be given if necessary.