<unk>  may be classified based on etiology into obstructive and non-obstructive types. Obstructive<unk> , is the most common type of<unk>   which may develop due to obstruction by foreign bodies, tumors and mucus plugs.<unk>  may also be classified based on duration of symptoms into acute and chronic types. Acute<unk>  is associated with airlessness due to recent lung collapse while chronic<unk>  involves a combination of infection, bronchial destruction, and fibrosis, in adition to airlessness.
Atelectasis classification
Empyema classification
Emphysema classification
Pulmonary edema classification
Pulmonary embolism classification
Chest pain classification
Silicosis classification
Hemoptysis classification