Obstructive vs restrictive lung disease: the comparison table
- Topic
Obstructive disease narrows the airways and air gets trapped; restrictive disease stiffens the lung or chest so it cannot fill.
What it is
Chronic lung diseases are split by lung function. In obstructive disease air flows out slowly: FEV1 falls more than FVC, so the FEV1/FVC ratio drops below about 0.7. In restrictive disease the lung or chest wall cannot expand, total lung capacity falls and the ratio stays normal or rises. Each group has its own lesions, and the pathologist links them to the numbers.
Step by step
- In obstruction the airway lumen is narrowed (mucus, wall thickening, spasm) or loses its outward pull (emphysema).
- Expiration becomes slow; air is trapped at the end of each breath and the chest hyperinflates.
- In interstitial restriction fibrosis stiffens the alveolar walls and lowers compliance.
- The stiff lung recoils hard, so airflow is fast for its small volume and the FEV1/FVC ratio is preserved.
- Thickened septa and lost capillaries reduce diffusion: exertional hypoxaemia and, later, pulmonary hypertension.
Obstructive vs restrictive
| Feature | Obstructive | Restrictive (interstitial) |
|---|---|---|
| Main problem | Resistance to airflow | Reduced expansion |
| FEV1/FVC | Low (below about 0.7) | Normal or high |
| Total lung capacity | Normal or high | Low |
| Examples | Emphysema, chronic bronchitis, asthma, bronchiectasis | Idiopathic pulmonary fibrosis, pneumoconioses, sarcoidosis |
| Typical sound | Wheeze | Fine end-inspiratory crackles |
| Lesion site | Bronchi, bronchioles, acinus | Alveolar septa and interstitium |
Clinical notes
- Wheeze and prolonged expiration point to obstruction; fine end-inspiratory crackles and clubbing point to interstitial fibrosis.
- Many patients mix both (asthma–COPD overlap; emphysema with fibrosis), so the numbers guide but the lesion decides.
Test yourself
Think of the answer, then tap the question to see it.
How does the FEV1/FVC ratio differ between obstructive and restrictive disease?
It falls below about 0.7 in obstruction and stays normal or rises in restriction, where FEV1 and FVC fall together.
What are the two groups of causes of restrictive physiology?
Chest-wall and neuromuscular disorders (obesity, kyphoscoliosis, pleural disease) and chronic interstitial diseases (fibrosis, pneumoconioses).
Which obstructive disease characteristically lowers DLCO?
Emphysema, because destroyed alveolar walls take their capillary bed with them.
Elsewhere in DurgiPedia
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Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: COPD (MedlinePlus, US National Library of Medicine, 2025); Interstitial Lung Disease (StatPearls (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.