Chronic Obstructive Pulmonary Disease (COPD) is a systemic and disabling pathological condition with a progressive course, characterized by lung function impairment with not fully reversible airflow limitation. It represents a major health problem worldwide and it is associated with substantial morbidity and mortality. In this book, the authors present current research on COPD including the clinical effects of continuous positive airway pressure therapy for COPD patients; anxiety and depression in patients with COPD; the role of non-invasive mechanical ventilation in the management of acute COPD; the immunology of COPD; multi-drug resistant bacteria in severe acute exacerbations of COPD requiring mechanical ventilation; and dietary prevention of COPD.