What is the phenomenon of post-renal acute kidney injury?

Post-renal acute kidney injury occurs specifically when there is an obstruction in the urinary tract that prevents urine from properly draining from the kidneys. This blockage can occur at various points along the urinary tract, including the ureters, bladder, or urethra. When urine cannot flow freely, it can back up into the kidneys, leading to increased pressure and ultimately resulting in damage to the kidney tissue. This condition differs from other types of acute kidney injury, which are characterized either by direct damage to the kidneys or by reduced blood flow. In post-renal cases, the primary issue lies with the obstruction affecting urine outflow rather than issues with the kidneys themselves or the blood supply.