Diminished blood flow to the kidneys causes prerenal failure. Such decreased flow may result from hypovolemia, shock, embolism, blood loss, sepsis, pooling of fluid in ascites or burns, or a
cardiovascular disorder, such as heart failure, arrhythmias, and tamponade. Other causes include disorders of the blood, such as idiopathic thrombocytopenic purpura, transfusion reactions, and other hemolytic disorders; malignant hypertension; and disorders resulting from childbirth-like bleeding (associated with placental abruption or placenta previa) that can damage the kidneys. Autoimmune disorders, such as scleroderma, can also cause acute renal failure.

Parenchymatous, or intrinsic, renal failure results from damage to the kidneys themselves, usually resulting from acute tubular necrosis. Such damage may also result from acute poststreptococcal glomerulonephritis, systemic lupus erythematosus, polyarteritis nodosa, vasculitis, sickle cell disease, bilateral renal vein thrombosis, nephrotoxins, ischemia, renal myeloma, and acute pyelonephritis.

Bilateral obstruction of urine outflow results in postrenal failure. Possible causes include renal calculi, clots, papillae from papillary necrosis, tumors, benign prostatic hyperplasia, strictures, and urethral edema from catheterization.