[heterogeneous group of noninfectious, nonmalignant disorders of the lower respiratory tract, affecting primarily the alveolar wall structures but also often involving the small airways and blood vessels of the lung parenchyma; may lead to respiratory insufficiency and death. ( CSP )] (UMLS (CSP) C0206062) =Disease or Syndrome ; =Lung Diseases; =ALLERG ALVEOL/PNEUM NOS; pneumoconiosis; pulmonary fibrosis/granuloma; ALLERG ALVEOL/PNEUM NOS; BO; histiocytosis X; pneumoconiosis; pulmonary fibrosis; Lung Sarcoidosis; Wegener's granulomatosis; radiation fibrosis; Anti-Glomerular Basement Membrane Disease