Acute Kidney Injury (AKI) is a sudden decline in kidney function that can develop over a short period. It can occur in connection with conditions such as severe illness, reduced blood flow to the kidneys, certain medicines, or direct kidney injury. AKI may sometimes produce few noticeable symptoms, while in other cases it can cause problems related to fluid, electrolyte, and waste accumulation. Diagnosis involves clinical assessment and laboratory testing, while treatment focuses on identifying and addressing the underlying cause. Some patients recover kidney function, while others may have persistent kidney damage or an increased risk of Chronic Kidney Disease. This article explains the causes, evaluation, treatment, and importance of follow-up after an episode of Acute Kidney Injury.