3. Coughing
Coughing, coughing, coughing. Because the pneumonia infection takes up residence in the lungs, this is where the frontline of the battle commences. As a result, phlegm and mucus build up, and coughing is one of the most common signs of the disease.
Be aware that coughing alone can be synonymous with many other conditions and infections, so always cross reference it with any other symptoms you (or the patient) are displaying.
Coughing may sometimes produce yellow or green mucus in the process of clearing the accumulation in the lungs. A sore throat can also be present, though not always, and can get worse over time if aggravated by coughing.