What pathogen causes pneumonia?

A pathogen is a germ that can cause illness. Bacterial pneumonia may follow a respiratory infection or develop on its own. Viral pneumonia can occur with illnesses such as influenza or COVID-19. Fungal causes are less common and are considered in particular health situations or after specific exposures. Different pathogens can produce similar symptoms, including cough, fever, chills, phlegm, tiredness and breathlessness. Symptoms alone cannot reliably identify the germ.

Contact a clinician if a cough is accompanied by fever, shortness of breath, chest pain, or worsening weakness. The assessment may include listening to your chest, checking oxygen levels and deciding whether a chest image or sample is useful. Antibiotics are used for some bacterial causes, not viral infections. Antifungal treatment is reserved for selected fungal infections. Follow the prescribed plan, drink fluids if you can, rest, and avoid smoking.

Seek emergency care for severe breathing difficulty, blue or grey lips, confusion, collapse, or unusual difficulty staying awake. Prompt review is also needed when fever or breathlessness is getting worse, chest pain is severe, or you are coughing blood. A serious infection can spread beyond the lungs and contribute to sepsis, which needs urgent treatment.

Ask which cause is suspected, whether a test could change treatment, how to take any prescribed medicine, and what improvement should look like during recovery.