In the United States, respiratory failure accounts for 1275 cases per 100,000 people. The etiology of respiratory failure can be diverse, encompassing obstructive and restrictive lung diseases, among others. The COVID-19 pandemic led to a significant surge in respiratory failure cases among patients admitted to hospitals, particularly those requiring intensive care. This book explores the pathophysiology of respiratory failure and insufficiency associated with COVID-19 illness as well as obstructive lung disease. It also delves into respiratory insufficiency stemming from liver disease and burns and discusses the role of veno-venous extracorporeal membrane oxygenation (VV-ECMO) in managing patients with respiratory insufficiency. This book is a useful resource for medical students, residents, physicians, and nurses alike.