<unk> s may be due to specific causes which can be intrinsic to the parenchyma of the lung, or extrinsic to it. Intrinsic * Pneumoconiosis caused by long-term exposure to dusts, especially in mining. For example, Asbestosis. * Radiation fibrosis, usually from the radiation given for cancer treatment. * Certain drugs such as amiodarone, bleomycin and methotrexate. * As a consequence of another disease such as rheumatoid arthritis. * Hypersensitivity pneumonitis due to an allergic reaction to inhaled particles. * Acute respiratory distress syndrome (ARDS), a severe lung condition occurring in response to a critical illness or injury. * Infant respiratory distress syndrome due to a deficiency of surfactant in the lungs of a baby born prematurely. * Tuberculosis Many cases of<unk>  are idiopathic (have no known cause). Still, there is generally pulmonary fibrosis. Examples are: * Idiopathic pulmonary fibrosis * Idiopathic interstitial pneumonia, of which there are several types * Sarcoidosis * Eosinophilic pneumonia * Lymphangioleiomyomatosis * Pulmonary Langerhans' cell histiocytosis * Pulmonary alveolar proteinosis Conditions specifically affecting the interstitium are called interstitial lung diseases. Extrinsic * Nonmuscular diseases of the upper thorax such as kyphosis, pectus carinatum and pectus excavatum. * Diseases restricting lower thoracic/abdominal volume (e.g. obesity, diaphragmatic hernia, or the presence of ascites). * Pleural thickening.
Restrictive lung disease
Obstructive lung disease
Alveolar lung disease
Reactive airway disease
Pulmonary heart disease
Interstitial lung disease
Asthma
Radiation-induced lung injury