Respiratory diseases are a group of pathological conditions that affect the lungs and other parts of the respiratory system. Some of its common types are common cold, influenza, chronic obstructive pulmonary disorder, pneumonia, acute asthma, lung cancer, tuberculosis, and severe acute respiratory syndrome. Respiratory diseases can be caused by tobacco smoking, infection, breathing second hand smoke, asbestos, radon and air pollution. Patients are examined by performing diagnostic tests, including, chest X-ray, ultrasound, blood test, lung biopsy, bronchoscopy, pulmonary function test, and CT scan. Treatments for respiratory diseases include medications, such as oral drugs, combination of inhalers, and intravenous treatment. Advanced procedures like interventional bronchoscopy, lung transplant, and stem cell therapy can also be used to treat respiratory diseases. Interventional bronchoscopy is a minimally invasive procedure used for the treatment of lung tumors, while lung transplant is appropriate for patients with severe or progressive respiratory conditions. This book outlines the mechanisms, diagnosis and treatment of respiratory diseases in detail. It will prove immensely beneficial to professionals and students involved in the study and treatment of these medical conditions at various levels.