Which of the following best describes the cause of post-renal acute kidney injury?

Post-renal acute kidney injury occurs as a result of an obstruction that affects the normal flow of urine from the kidneys. This obstruction can occur anywhere within the urinary tract, including the ureters, bladder, or urethra, leading to an increase in pressure within the urinary system. When this happens, it can impede the filtration function of the kidneys, causing them to fail to properly filter waste from the blood.

In this context, urinary tract obstruction specifically refers to the blockage that prevents urine from exiting the kidneys, contributing to the development of post-renal acute kidney injury. This obstruction can be caused by various factors such as kidney stones, tumors, or prostate enlargement. Understanding this relationship helps clarify why the obstruction within the urinary tract is pivotal in causing post-renal issues, differentiating it from other types of acute kidney injury, such as pre-renal or intrinsic renal injuries which have different underlying causes.