Emphysema

Emphysema is swelling or distension of lung tissue caused by air trapped in the interstitial spaces of connective tissue or inter-alveolar tissue.

Sub-cutaneous emphysema : swelling produced by the introduction of air or release of gas in subcutaneous cellular tissue.

Pulmonary emphysema : excessive permanent dilatation of the pulmonary alveoli, with rupture of their septa.