This book comprehensively covers pulmonary vascular disease and its relation to lung disease. Pulmonary vascular disease is a major complication of all types of lung disease including smoking related lung disease (COPD, emphysema) and interstitial lung disease, serving as significant source of morbidity and mortality in these patients. The co-evolution of lung disease and vascular disease is a very interesting area of research activity in an attempt both to understand and seek treatments for disease of the lung as well as to risk stratify and prevent the development of pulmonary hypertension in these patients. At the same time, there is significant clinical interest in diagnosing, phenotyping and treating patients with lung disease complicated by pulmonary hypertension, in part due to several new mechanistic agents that are coming to the market for treatment of pulmonary hypertension, as well as the first ever large positive clinical trial of the treatment of pulmonary hypertension-associated with ILD. These chapters, written by experts in the field, bring together topics spanning the biology, pathophysiology and clinical diagnosis and treatment of pulmonary vascular disease in the context of chronic lung diseases. It also spans all major types of lung disease, dividing the topics based on pathophysiology as well as clinical phenotype. It contains within it both the latest research directions in the field for the research driven reader, but also the clinical recommendations and the pathways of likely clinical development in the field for both the treating clinicians as well as the clinical opinion leaders and directors of clinical research. This is an ideal guide for pulmonary physicians taking care of patients with lung disease or pulmonary hypertension, cardiologists taking care of pulmonary hypertension patients with lung disease, rheumatologists, and translational researchers in the field of lung biology and pulmonary vascular physiology.