The healing time of acute renal failure ranges from a few days to a few months depending on the primary disease, and some of them cannot be cured effectively, and even some of them will be transformed into chronic renal failure. The causes of acute renal failure are categorized into pre-renal, renal and post-renal. If the cause of acute renal failure is pre-renal or post-renal, such as pre-renal acute renal failure caused by massive blood loss, blood volume insufficiency due to dehydration, or post-renal renal failure caused by obstruction, most of them can be fully recovered within a few days to a few weeks after symptomatic treatment. If the acute renal failure is caused by renal causes, such as drug-induced renal injury, the recovery time is relatively longer and may take several months to return to normal. Some acute renal failure cannot be completely cured and may turn into chronic renal failure. Patients with acute renal failure are advised to go to regular hospitals in time and follow the doctor’s instructions to avoid delaying their condition.