Acute kidney injury is defined as a significant decline in kidney function that occurs over a short period of time – meaning just a few hours or days. It is a very common, but also very serious, condition in patients who are in the hospital, especially among those receiving intensive care. Acute kidney injury may occur due to the failure of other organs such as the heart or liver, an allergic reaction, diarrhea that causes fluid loss, and other problems that impede the flow of blood to the kidneys. It can also occur due to kidney damage sustained from sepsis, scleroderma, vasculitis or other direct causes, or it may occur due to a urinary tract obstruction caused by a blood clot, kidney stone, enlarged prostate or possibly a malignant mass. Treatment for acute kidney injury will depend on its cause but typically requires hospitalization along with fluids, medications and possibly kidney dialysis.