Acute renal failure is a medical condition characterized by the sudden loss of kidney function. It is also known as acute kidney injury. There are several synonyms for acute renal failure, including acute kidney failure, acute renal insufficiency, acute kidney injury syndrome, and acute renal necrosis. These terms all describe the same condition where the kidneys suddenly stop working and cannot filter waste products from the blood. Acute renal failure can be caused by a range of factors, such as dehydration, infections, medications, and underlying health conditions. It is important to seek prompt medical attention if any symptoms of acute renal failure are experienced, such as decreased urine output, swelling, and confusion.