[Acute renal failure in geriatrics].

Acute renal failure (ARF) is a frequent medical problem, affecting 20% of hospitalized patients. Aging leads to functional changes in the kidney, disruptions to hydrosodium homeostasis, and is associated with a higher prevalence of chronic kidney disease due to the impact of numerous chronic illnesses (diabetes, arterial hypertension, benign prostatic hypertrophy, etc.). All these age-related impairments hamper the kidney's ability to adapt to acute events. While elderly subjects can develop all types of AKI, they are particularly at risk of iatrogenic AKI due to polymedication, functional AKI due to a change in their ability to maintain hydrosodium homeostasis, and obstructive AKI linked to urological pathologies.