VHOSPITAL.CLINIC · Differential Diagnosis
Bronchitis vs Pneumonia
Clinical comparison — shared symptoms, key differences, distinguishing diagnostic tests, treatment pathways, and when to seek urgent evaluation.
Condition Overview
Condition A
Bronchitis
Bronchitis is inflammation of the bronchial tubes that carry air to the lungs. Acute bronchitis is usually caused by viruses and resolves in 2–3 weeks. Chronic bronchitis is a form of COPD caused by long-term irritation, often from smoking.
Condition B
Pneumonia
Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs, which may fill with fluid or pus. It can be caused by bacteria, viruses, or fungi and ranges from mild to life-threatening.
Shared Symptoms — Why They're Confused
Both conditions present with 5 overlapping symptoms, making clinical differentiation essential.
Key Clinical Differences
Bronchitis
- Productive cough with purulent sputum
- Fever that is low-grade in bronchitis vs high in pneumonia
- Wheeze common in bronchitis; crackles in pneumonia
Pneumonia
- Localised alveolar infection with systemic signs
- High fever (>38.5°C), rigors, pleuritic chest pain
- Dullness to percussion and bronchial breathing on exam
- Hypoxia in moderate-to-severe pneumonia
Distinguishing Diagnostic Tests
| Test | Bronchitis | Pneumonia |
|---|---|---|
| Chest X-ray | Normal or peribronchial thickening — no consolidation | Lobar or segmental consolidation — air bronchograms |
| C-reactive protein (CRP) | <20 mg/L — mild inflammatory response | >100 mg/L in bacterial pneumonia — significant infection |
| SpO2 | Normal (≥95%) — bronchitis rarely causes hypoxia | May be <94% — alveolar filling reduces gas exchange |
Treatment Approaches
Bronchitis
- •Supportive care: fluids, rest
- •Antibiotics only if bacterial (purulent green sputum, fever >3 days)
- •Bronchodilators for wheeze
Pneumonia
- •Antibiotics: amoxicillin or azithromycin (outpatient)
- •Hospitalise if CURB-65 ≥2
- •Oxygen supplementation if SpO2 <94%
When Doctors Consider Each Diagnosis
🔵 Consider Bronchitis when:
- →Low-grade fever, wheeze, normal chest X-ray
- →Productive cough improving after 1–2 weeks
🟢 Consider Pneumonia when:
- →High fever, pleuritic pain, consolidation on X-ray
- →SpO2 dropping, systemically unwell patient
Explore Each Condition in Detail
Related Clinical Pages
Bronchitis
Medical References
Content on this page is informed by evidence-based clinical sources including:
- World Health Organization (WHO)Global health guidance and disease classification
- National Health Service (NHS)UK clinical guidelines and patient information
- National Institute for Health and Care Excellence (NICE)Evidence-based clinical practice guidelines
- Centers for Disease Control and Prevention (CDC)US public health data and clinical recommendations
- PubMed – NCBIPeer-reviewed biomedical literature and clinical studies
- Cochrane LibrarySystematic reviews and meta-analyses in evidence-based medicine
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