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Categories: Respiratory Diseases

A condition in which there is air or gas in tissues that
normally have none, or an excess of air in tissues that normally contain a

certain quantity of it. A condition of the lungs characterized by a

permanent dilation of the air cells of the lung with dwindling of the air

cell walls and the blood vessels, resulting in a loss of the normal

elasticity of the lung tissue.

Causes. Heredity; it occurs in glass blowers, in musicians using wind

instruments. It occurs also after whooping-cough, asthma, etc.