Interstitial lung diseases are a diverse group of acute and chronic pulmonary disorders characterized by a variable amount of inflammation and/or fibrosis. In Interstitial Lung Disease: Causes, Diagnosis and Treatment, the authors explore the role of genetics in the pathogenesis of interstitial lung diseases, as well as develop new diagnostic modalities and identify novel therapeutic targets. This compilation goes on to discuss acute infiltrative lung disease, a heterogeneous group of lung disorders characterized by diffuse parenchymal lung involvement. This group of infiltrative lung diseases may result in five histopathological presentations: diffuse alveolar damage, diffuse alveolar hemorrhage, immunoallergic pneumonia, acute organizing pneumonia and acute eosinophilic pneumonia. High-resolution computed tomography is proposed as a more sensitive and accurate method in diagnosing interstitial lung disease through specific patterns which are highly suggestive of a subtype of interstitial pneumonia. High-resolution computed tomography is also proposed for the diagnosis of sarcoidosis, a systemic granulomatous disease which involves the lungs in more than 90% of cases. It is one of the leading causes of interstitial involvement in lung diseases, and its diagnosis is based on compatible clinical, biological, imaging and anatomopathological features. The closing chapter aims to identify diagnostic procedures for the early diagnosis of cardio-pulmonary complications, delineate a proper methodology to monitor complications, and define therapeutic guidelines.