Pneumonia Home A-Z Health Information Health Library A-Z Pneumonia Overview Pneumonia is an infection of the lungs that can be caused by bacteria, viruses, and fungi. Causes and risk factors Pneumonia is most commonly caused by bacteria, particularly Streptococcus pneumoniae.Other bacterial pathogens include Haemophilus influenzae and Staphylococcus aureus.Viral causative agents include Influenza A (including H1N1), COVID-19, CMV a. Symptoms FeverProductive cough with purulent sputum (often yellow or green)Mostly dry cough during viral pneumoniaChest pain, which may be pleuritic (sharp pain that worsens with breathing or coughing)Shortness of breathMalaise, headache and muscle aches Diagnosis Chest X-ray typically shows a dense area of lung infection in one or more lobes of the lungs.Blood tests may show elevated white blood cell counts.Sputum culture can identify the causative bacteria.Throat swabs can also be used for diagnosis.Occasionally, CT chest and bronchoscopy are also required. Treatment Pneumonia is treated with antibiotics that target common bacterial pathogens.Pneumonia caused by viruses can be treated with antiviral medications.Supportive care, including rest, hydration and symptom management, is also important for complete treatment.Hospitalisation may be required for severe cases, especially in elderly or immunocompromised patients. Prevention Yearly vaccination for must be done to prevent influenza. Pneumococcal vaccination is recommended for old age patients suffering from lung disease and immunocompromised individuals.