What are the causes of oliguria and anuria?

Clinically, generally 24 hours urine volume is less than 400ml, called oliguria 24 hours urine volume is less than 100ml called anuria. The causes of oliguria or anuria, there are three kinds of common. First, prerenal factors, various reasons caused by systemic effective, blood flow decreased, resulting in renal blood flow decreased, resulting in renal filtration pressure decreased, resulting in decreased urine volume. Second, renal factors, various causes of renal substantial damage caused by oliguria or anuria are more common acute nephritis, nephrotic syndrome, etc. Third, renal factors, various causes of kidney urine can not be discharged or resistance is relatively large to be discharged from the body, can cause oliguria or anuria, clinical more common ureteral stones, prostate hyperplasia, urethral stones and other manifestations.