Early pneumonia signs can be nonspecific and resemble a common respiratory infection: fatigue, reduced appetite, low-grade fever, headache, and cough. Over time, cough may intensify, sputum may appear, and shortness of breath can develop. Some people notice pleuritic chest pain—sharp discomfort that worsens with deep breathing—early in the course. In older adults, fever may be absent and early signs may include confusion, excessive sleepiness, or sudden functional decline. If symptoms accelerate over 24–72 hours—especially with breathlessness, high fever, chest pain, or low oxygen levels—prompt clinical assessment is warranted.