Pulmonary fibrosis

Chronic interstitial lung disease characterized by progressive fibrosis of the pulmonary parenchyma, leading to reduced lung compliance, impaired gas exchange, restrictive ventilatory defect, and resultant exertional dyspnea and hypoxemia. Possible causes are idiopathic, enviromental (asbestosis, silicosis, coal workers' pneumoconiosis), autoimmune disease (rheumatoid arthritis, Lupus, scleroderma), medications (amiodarone, nitrofurantoin, methotrexate), radiotherapy, allergic pneumonitis (molds, bacteria, bird feather), long-lasting smoking, and chronic acid reflux (GERD).