<unk>  is the result of any of several abnormal pathophysiological occurrences. Structural abnormalities of the junctions between the kidney, ureter and bladder that lead to<unk>  can occur during fetal development. Some of these congenital defects have been identified as inherited conditions, however, the benefits of linking genetic testing to early diagnosis have not been determined. Other structural abnormalities could be caused by injury, surgery, or radiation therapy. The most common causes of<unk>  in children are anatomical abnormalities. These include vesicoureteral reflux, urethral stricture, and stenosis. The most common cause of<unk>  in young adults is kidney stones. In older adults, the most common cause of<unk>  is benign prostate hyperplasia (BPH), or intrapelvic neoplasms such as prostate cancer. Compression of one or both ureters can also be caused by other developmental defects not completely occurring during the fetal stage such as an abnormally placed vein, artery, or tumor. Bilateral compression of the ureters can occur during pregnancy due to enlargement of the uterus. Changes in hormone levels during this time may also affect the muscle contractions of the bladder, further complicating this condition. Sources of obstruction that can arise from other various causes include kidney stones, blood clots or retroperitoneal fibrosis. The obstruction may be either partial or complete, and can occur anywhere from the urethral meatus to the renal calyces.<unk>  can also result from the retrograde flow of urine from the bladder back into the kidneys (vesicoureteral reflux), which can be caused by some of the factors listed above as well as compression of the bladder outlet into the urethra by prostate enlargement or fecal impaction in the rectum (which sits immediately behind the prostate), as well as abnormal contractions of bladder detrusor muscles resulting from neurological dysfunction (neurogenic bladder) or other muscular disorders.
Hydronephrosis
Pyonephrosis
Glomerulonephrosis
Pyelonephritis
Ureteric stricture
Ureteral cancer
Salpingitis
Obstructive uropathy