Final answer:
Post-renal acute kidney injury is caused by an obstruction of the flow of urine often due to factors like kidney stones or other obstructions in the urinary tract.
Step-by-step explanation:
Acute kidney injury from post-renal etiology is caused by obstruction of the flow of urine. This can happen for various reasons, including kidney stones, tumors like renal cell carcinoma or Wilm's tumor, and other conditions such as hydronephrosis—itself caused by an obstruction leading to kidney enlargement. By contrast, conditions that interfere with renal perfusion, hypovolemia or decreased cardiac output, and conditions that act directly on functioning kidney tissue cause pre-renal and intrinsic renal causes of acute kidney injury, respectively.