The clinical presentations of<unk><unk>  depend on the frequency, length, exposure, and duration of illness. Due to a lot of variation in the the presentation<unk><unk>  has been classified according to various schemes.<unk><unk>  may be classified into several subtypes based on various classifications methods such as classical classification, boyd classification, cormier classification, and selman classification.
Hypersensitivity pneumonitis classification
Eosinophilic pneumonia classification
Idiopathic interstitial pneumonia classification
Pneumoconiosis classification
Bronchiectasis classification
Idiopathic pulmonary fibrosis classification
Lipoid pneumonia classification
Empyema classification