Chart — Pulmonary Diseases
COPD vs Asthma Chart
COPD and asthma are both obstructive, but they differ in who gets them, how reversible the obstruction is, and what the acute gas is telling you. This chart lines them up feature by feature, including where their emergency treatment overlaps and where it splits.
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
COPD vs Asthma Side by Side
| Feature | COPD | Asthma |
|---|---|---|
| Onset | Usually after 40, with a smoking history | Often childhood or young adulthood, with atopy |
| Airflow limitation | Persistent, largely irreversible or only partially reversible | Variable, largely reversible |
| Triggers | Respiratory infection, pollutants | Allergens, exercise, irritants, viral infection |
| Reversibility on spirometry | Limited bronchodilator response | Significant FEV1 improvement post-bronchodilator |
| Course | Progressive over time | Episodic, with good intervals between flares |
| Inflammation | Neutrophilic | Typically eosinophilic |
| Comorbid features | Chronic bronchitis, emphysema | Atopy, allergic rhinitis |
| Acute treatment overlap | O₂ to target, SABA ± SAMA, systemic steroids; COPD adds NIV for hypercapnic acidosis | O₂ to target, SABA ± SAMA, systemic steroids; severe asthma adds magnesium |
| ABG in severe disease | Chronic compensated hypercapnia at baseline | A normalizing or rising CO₂ is a RED FLAG of fatigue |
Clinical Notes
- Overlap is real.Some patients have features of both — asthma-COPD overlap (ACO) — so the two diagnoses are not always mutually exclusive.
- A normal or rising CO₂ in acute severe asthma is an emergency. An asthmatic in a severe attack should be blowing the CO₂ off; a PaCO₂ that climbs back to normal and then keeps rising signals respiratory muscle fatigue and impending failure, not improvement.
- Mind the COPD oxygen target. Titrate the known or suspected COPD patient to an SpO₂ of 88–92% to avoid blunting respiratory drive and worsening hypercapnia.
Related Resources
Sources
- Global Initiative for Chronic Obstructive Lung Disease. Global Strategy for Prevention, Diagnosis and Management of Chronic Obstructive Pulmonary Disease (current annual report). GOLD.
- Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention (current annual report). GINA.