These systemic symptoms are what often distinguish acute pyelonephritis from a lower urinary tract infection.

这些全身症状常可用来区分急性肾盂肾炎和下尿路感染。

All right, as a quick recap: acute pyelonephritis is typically a bacterial infection of the upper urinary tract, which usually develops from a lower urinary tract infection, especially in individuals with vesicoureteral reflux.

得！快速回顾一下：急性肾盂肾炎是一种典型的上尿路细菌感染，通常由下尿路感染发展而来，尤其在膀胱输尿管反流患者中。

Acute pyelonephritis is most often caused by ascending infection: meaning bacteria start by colonizing the urethra and bladder, which would be a lower urinary tract infection, and make their way up the ureter to the kidney.

急性肾盂肾炎最常见的感染途径是上行性感染，即细菌先占领膀胱和尿道（这会是下尿路感染），然后这些细菌向上感染输尿管到肾。