Acute Lung Injury (ALI) is a severe, acute inflammatory process affecting the lungs, characterized by diffuse alveolar damage, increased pulmonary vascular permeability, and non-cardiogenic pulmonary edema. It results in impaired gas exchange and hypoxemia. ALI can be triggered by various direct or indirect insults, including sepsis, pneumonia, trauma, and aspiration. Management focuses on supportive care, addressing the underlying cause, and optimizing ventilation strategies to minimize further lung damage.