The common causes of hydronephrosis are as follows: 1. Calculous diseases. For example, after kidney stones, ureteral stones and urethral stones block the urinary tract, the urine in the renal pelvis cannot be discharged, which will cause hydronephrosis. 2. Tumor related diseases. For example, kidney cancer, bladder cancer, prostate cancer, etc. 3. Stenosis. For example, congenital dysplasia leads to ureteral stricture, urethral stricture, etc. 4. Compression of adjacent tissues of urinary system. Such as the enlarged uterus after pregnancy. Although mild hydronephrosis is not harmful to human body and kidney, it should be paid attention to and should be reviewed regularly. If it is serious hydronephrosis, it is easy to cause chronic obstructive nephropathy, so surgery is needed.
