While classical descriptions of pneumonia include histopathologic “stages” (e.g., congestion and hepatization), modern practice more often focuses on clinical severity and recovery phases. Early disease may present with fever, cough, and fatigue, while progression can involve shortness of breath, declining oxygen saturation, and systemic toxicity. With treatment, the goal is clinical stabilization—improving breathing, normalizing vitals, and restoring functional status. Radiographic resolution typically lags behind symptom improvement, so persistent imaging changes do not necessarily mean clinical failure. In real-world terms, “stages” are used as an operational lens to recognize early deterioration, monitor for complications, and structure follow-up appropriately.