Insufficient blood supply to the kidneys

Blood loss

Loss of large amounts of sodium and fluid

Physical injury that blocks blood vessels

Inadequate pumping of the heart (heart failure)

Extremely low blood pressure (shock)

Liver failure (hepatorenal syndrome)

Medications that decrease blood flow to the kidneys

Injury to the kidneys

Blood supply to the kidneys decreased long enough to damage the kidneys

Toxic substances (for example, medications, iodinated contrast agents used in imaging tests, and poisons)

Rhabdomyolysis (toxic effect to the kidneys caused by excessive muscle breakdown)

Allergic reactions (for example, to certain antibiotics)

Disorders affecting the filtering units (nephrons) of the kidneys (for example, acute glomerulonephritis, tubulointerstitial nephritis, tumors damaging the kidneys, or injury to blood vessels as occurs with hemolytic-uremic syndrome, systemic lupus erythematosus [lupus], atheroembolic kidney disease, Goodpasture syndrome, granulomatosis with polyangiitis, or microscopic polyangiitis)

Serious bodywide infection (sepsis)

Obstructed urine flow

Blockage (obstruction) of the bladder (for example, by an enlarged prostate, narrowing of the urethra, or bladder cancer)

Tumor pressing on the urinary tract

Stones in the ureters or bladder

Obstruction within the kidneys (for example, by crystals or stones such as oxalate or uric acid)