Acute renal failure, also known as acute kidney injury (AKI), is a sudden and rapid decline in kidney function, leading to the inability of the kidneys to adequately filter waste products and maintain fluid and electrolyte balance in the body. This condition can arise from various causes, such as severe infections, dehydration, major surgeries, or exposure to certain toxins. The hallmark of acute renal failure is a sudden increase in serum creatinine levels and a decrease in urine output. The condition is categorized into three stages based on the severity of impairment: prerenal, intrinsic renal, and postrenal. Prerenal causes involve decreased blood flow to the kidneys, intrinsic renal causes relate to damage within the kidneys themselves, and postrenal causes result from obstruction of urinary flow. Prompt identification and management of the underlying cause are crucial in preventing further kidney damage and improving outcomes for individuals experiencing acute renal failure. Treatment may involve addressing the underlying condition, providing supportive care, and in severe cases, renal replacement therapy such as dialysis may be necessary to assist in kidney function until recovery occurs.