Community-acquired pneumonia

Audience: Patients and providers
Status: Clinical guide · patient + provider
Last updated: 2026-03-27

1. Clinical overview

Community-acquired pneumonia is an acute lower respiratory infection acquired outside the hospital setting, and management hinges on severity assessment, site-of-care decisions, and appropriately narrow empiric therapy.

2. Common causes and risk factors

• Streptococcus pneumoniae, Haemophilus influenzae, atypical organisms, and respiratory viruses are common causes.
• Older age, COPD, heart failure, immunocompromise, smoking, and aspiration risk increase severity risk.

3. Typical symptoms

• Cough, fever, dyspnea, pleuritic pain, fatigue, sputum production, and abnormal vital signs.

4. Diagnosis and evaluation

• Confirm pneumonia syndrome clinically and with indicated imaging or testing.
• Use severity tools and clinical judgment to guide outpatient versus inpatient management.
• Review comorbidities, recent antibiotic exposure, oxygen needs, and aspiration risk.

5. Treatment (non-pharmacologic)

• Hydration, rest, smoking cessation support, and return-precaution counseling.
• Optimize influenza and pneumococcal vaccination after recovery when indicated.

6. Treatment (pharmacologic)

• Stable outpatients without major comorbidity may receive amoxicillin, doxycycline, or azithromycin when local macrolide resistance allows.
• Outpatients with comorbidity commonly receive amoxicillin/clavulanate plus azithromycin or doxycycline, or monotherapy with a respiratory fluoroquinolone such as levofloxacin.
• Inpatient regimens often use ceftriaxone plus azithromycin or a respiratory fluoroquinolone, with narrowing once culture or diagnostic data return.

7. Monitoring and follow-up

• Reassess for clinical stability, oxygenation, fever curve, and symptom trajectory within 48 to 72 hours if risk is high.
• Delayed radiographic recovery is common; clinical response matters more than immediate imaging normalization.

8. Practical counseling points

• Explain when cough and fatigue may persist despite microbiologic improvement.
• Review red flags clearly: worsening dyspnea, confusion, chest pain, low intake, or inability to take medication.
• Reinforce adherence to the full prescribed regimen unless changed by a clinician.

9. Red flags and escalation

• Escalate urgently for hypoxia, hypotension, confusion, sepsis concern, or inability to maintain oral intake.
• Reevaluate for resistant pathogen, empyema, PE, or alternate diagnosis if recovery stalls.

10. Guideline references

• ATS/IDSA community-acquired pneumonia guideline.
• CDC adult immunization guidance.
• Antibiotic stewardship best practices for respiratory infections.

Note: Educational guide only; not a substitute for individualized medical care.