Community-acquired Pneumonia
Community-acquired pneumonia (CAP) is acute infection of lung tissue acquired outside hospital, causing respiratory symptoms with compatible examination or imaging findings.
Key takeaways
- Cough, fever and chest pain are common, but older adults may present mainly with confusion or functional decline.
- Oxygen level, breathing rate, blood pressure, age and comorbidities help determine whether hospital care is needed.
- Empirical antibiotics reflect likely organisms and severity, then should be reviewed against tests and clinical response.
The listings below do not confirm CAP or determine safe place of care; respiratory assessment is required.
Confirming and grading illness
Chest X-ray often supports diagnosis, while pulse oximetry is essential. Blood or sputum testing is more useful in severe disease or when resistant organisms are plausible. Viral testing can affect infection control and antiviral decisions but does not always exclude bacterial co-infection.
Treatment and reassessment
Regimens differ for outpatient and inpatient care and according to allergy, recent antibiotics and local resistance. Hydration, oxygen and management of sepsis or pleural complications may be needed. Failure to improve prompts review for empyema, abscess, obstruction, resistant infection or a non-infectious mimic.
When to seek urgent care
Seek emergency care for severe breathlessness, blue or grey lips, confusion, fainting, chest pain, coughing blood, very low urine output or inability to keep fluids down.