Causes of Postrenal Failure
Intratubular obstruction
Uric acid nephropathy
Methotrexate crystal deposition
Ureteric obstruction
Retroperitoneal carcinoma (cervix, prostate, uterus) or sarcoma
Retroperitoneal fibrosis
Intrinsic causes
Nephrolithiasis
Necrotic papillae (papillary necrosis)
Blood clots
Urethral obstruction
Prostatic hypertrophy
Blood clots
Bladder dysfunction (e.g., flaccid bladder in diabetes)
Blocked Foley catheter