急性肾衰可表现尿少,但尿少绝不就是肾衰,尿不减少也不一定不是肾衰。健康成人每昼夜排尿量在1500毫升左右,平均每分钟1毫升。如果每日尿量少于400毫升,谓之少尿,少于100毫升称为无尿或尿闭。根据病变部位,少尿原因可分为肾前性、肾性和肾后性三大类。肾前性少尿是由于血容量不足或心排出量不足导致肾血流量降低,肾小球滤过液量减少,和肾小管再吸收增强所形成的。这是一种功能性少尿,肾脏无器质性改变。经过治疗,肾血流量恢复,尿量即可增加。如不予迅速纠正,则可导致肾实质损害形成急性肾衰。肾后性少尿并非肾脏泌尿功能不良,而是由于上尿路梗阻或破裂,肾脏分泌的尿液积存于上尿路或经破裂处外渗未经膀胱尿道排出体外。解除梗阻或修补破损即可恢复正常排尿。肾性少尿与上述二种不同,是由于肾前因素或肾毒物质引起了肾脏器质性损害,导致泌尿功能衰竭(即一般指的急 Acute renal failure can show less urine, but urine is by no means renal failure, urine is not necessarily not reduced renal failure. Healthy adults urinary output per day and night at about 1500 ml, with an average of 1 ml per minute. If the daily urine output is less than 400 milliliters, less oliguria, less than 100 milliliters is called anuria or urinary incontinence. According to the lesion, oliguria causes can be divided into pre-renal, renal and renal three categories. Prerenal oliguria is due to insufficient blood volume or lack of cardiac output resulting in decreased renal blood flow, decreased glomerular filtration fluid, and increased renal tubular reabsorption formed. This is a functional oliguria, kidney no organic changes. After treatment, renal blood flow recovery, urine output can be increased. If not corrected quickly, can lead to renal parenchymal damage to acute renal failure. Renal oliguria is not renal urinary dysfunction, but due to obstruction or rupture of the upper urinary tract, the urine secreted by the kidneys in the upper urinary tract or ruptured by extravasation without excretion of the bladder and urethra. Relieve obstruction or repair damage can be restored to normal urination. Renal oliguria and the above two different, is due to prerenal factors or renal toxic substances caused by renal organic damage, leading to urinary failure (that is, the general refers to the urgency