Clinical exam · Respiratory system
Pulmonary hyperinflation syndrome (emphysema) !
- Syndrome
The lungs stay full of trapped air: barrel chest, a hollow percussion note and breathing that is almost inaudible.
Updated 2026-11-01
See it in 3D: Diaphragm · Ribs (back part) · Sternum
What it is
Hyperinflation is a lasting increase of air in the lungs at the end of expiration. Its typical chronic form is emphysema, in which alveolar walls are destroyed and the elastic recoil that helps push air out is lost. The findings are bilateral and symmetric, unlike the focal syndromes.
Key findings
- A barrel chest alone is not specific; it gains value with hyperresonance and prolonged expiration.
- A forced expiration lasting more than 6 seconds suggests obstruction.
Pathophysiology
- In emphysema alveolar septa are destroyed, leaving large air spaces with less exchange surface.
- Without elastic recoil, small airways collapse on expiration and air is trapped.
- The diaphragm descends and flattens; when it contracts it pulls the costal margin inward (Hoover sign).
- The distended lung covers the heart and liver and reduces their areas of dullness.
| Inspection | Palpation (fremitus) | Percussion | Auscultation |
|---|---|---|---|
| Barrel chest, pursed lips, accessory muscles, Hoover sign; trachea midline | Expansion and fremitus reduced on both sides | Hyperresonance; low bases, excursion ↓; cardiac dullness ↓ | Very faint breath sounds, prolonged expiration; distant heart sounds |
Common causes
- COPD with predominant emphysema (smoking, wood smoke).
- Alpha-1 antitrypsin deficiency in young adults.
- Severe asthma attack (acute hyperinflation).
- Over time, pulmonary hypertension and cor pulmonale.
Tests that confirm it
- Spirometry with non-reversible obstruction.
- Radiograph: flat diaphragms, wide intercostal spaces, a larger retrosternal space.
- CT to quantify emphysema and bullae.
Test yourself
Think of the answer, then tap the question to see it.
What is the Hoover sign?
Inward movement of the lower costal margin on inspiration from a flattened diaphragm; typical of hyperinflation.
What happens to cardiac dullness in emphysema?
It shrinks, because the hyperinflated lung covers the heart.
Which pleural complication can emphysematous bullae cause?
Secondary spontaneous pneumothorax when a bulla ruptures.
See it in 3D
The structures of Durgical's 3D anatomy where it is found.
Related
- The pleuropulmonary syndromes: the comparison table to know
- Bronchial obstruction syndrome
- Chest inspection: shape, expansion, accessory muscles and retractions
- Chest percussion: resonance, dullness and hyperresonance
Related conditions
- Chronic obstructive pulmonary disease (COPD)
- Asthma
- Pneumothorax
- Pulmonary hypertension and cor pulmonale
Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.
Sources: Chronic obstructive pulmonary disease (COPD): MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2024); Breath sounds: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2024).
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Representative model, for educational purposes only.