Untreated pneumonia can progress and substantially increase complication risk. Oxygen exchange can deteriorate, respiratory failure may develop, and hospitalization or ICU care can become necessary. Complications may include pleural effusion/empyema, lung abscess, or systemic infection such as sepsis. Risk is higher in older adults, people with chronic diseases, and immunocompromised patients. Recovery can also take longer with more pronounced functional decline. For these reasons, early evaluation and an appropriate treatment plan are critical when pneumonia is suspected. Even with home monitoring, clear deterioration triggers should be established so medical care can be sought without delay.