Lung infections typically manifest with distinct symptoms. The most common signs include high fever, cough, chest pain, and shortness of breath. If these symptoms are not addressed promptly, the infection can progress and lead to serious complications. Other potential symptoms may include a productive cough (which may contain greenish, yellow, or sometimes bloody mucus), sweating and chills, difficulty breathing, chest pain exacerbated by breathing or coughing, loss of appetite, fatigue, nausea, vomiting, and diarrhea.