Pneumonia is an infection-driven inflammation of lung tissue. It can be mild in some people, but in others it may progress to severe respiratory distress or failure. Severity depends on age, immune status, chronic diseases (COPD, heart failure, diabetes), smoking, and the causative pathogen. Community-acquired pneumonia is most common, while hospital-acquired cases are more likely to involve resistant organisms. Accurate diagnosis (clinical assessment plus chest imaging and selected tests) and risk stratification guide treatment. In older adults, presentation can differ—confusion or sudden functional decline may occur instead of high fever. Pneumonia should be managed through structured clinical care, not a “wait it out” strategy.