Community-acquired pneumonia is a lung infection that starts outside the hospital, most often caused by Streptococcus pneumoniae. It ranges from a mild illness treated at home to sepsis and respiratory failure, so judging severity guides where and how to treat.
Key symptoms
- Cough with sputum
- Fever, chills and sweats
- Shortness of breath and pleuritic chest pain
- Fatigue; in older adults confusion or falls may be the only sign
What you find on exam
- Fever, fast breathing, tachycardia, low oxygen saturation
- Focal crackles, bronchial breath sounds
- Dullness to percussion and increased tactile fremitus over consolidation
- Blood pressure and mental status to judge severity
Tests
- Chest X-ray: new infiltrate confirms the diagnosis
- Blood count, metabolic panel, lactate if septic
- Blood and sputum cultures in severe or hospitalized cases
- CURB-65 or PSI score to decide outpatient vs hospital care
- Influenza and COVID-19 testing; urinary antigens when severe
Treatment basics
- Healthy outpatient: amoxicillin, or doxycycline
- Outpatient with comorbidities: amoxicillin-clavulanate plus azithromycin, or levofloxacin
- Inpatient: ceftriaxone plus azithromycin
- Oxygen, fluids and early antibiotics for sepsis
- Usually 5 days of antibiotics if improving; pneumococcal and influenza vaccines
Red flags
- Confusion, low blood pressure or breathing rate 30 or more
- Oxygen saturation below 92 percent
- Signs of sepsis or failure to improve after 48 to 72 hours
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; NCSBN 2026 NCLEX-RN Test Plan. Written by Making Synapses. Making Synapses is not affiliated with these organizations.