The lungs are two air-filled and spongy organs that are situated on either side of the chest. The heart and lungs work together to make sure the body receives enough supply of oxygen. Lung diseases are a variety of conditions or diseases that impair the ability of the lungs to function normally. These diseases can have an impact on pulmonary function and the capacity to breathe. Lung diseases can be classified into three types, including lung circulation diseases, airway diseases and lung tissue diseases. The major causes of lung diseases include infections, air pollution and smoking. The other significant risk factor for these diseases is genetics. The most common types of lung diseases include asthma, bronchitis, pneumonia, chronic obstructive pulmonary disease (COPD), lung cancer, pulmonary fibrosis, etc. This book explores all the important aspects of lung diseases in the modern day. It will help new researchers by foregrounding their knowledge on these medical conditions. Such selected concepts that redefine the diagnosis and treatment of these diseases through an evidence-based approach have been presented in this book.