Problems related to the respiratory system are among the first reasons for applying to emergency clinics. As a result of air pollution, climate changes, increasing air pollution, the emergence of new microorganisms that affect the respiratory system, chemical irritants, and the increase in malignant diseases of the respiratory system, emergency service applications are also increasing. In patients admitted to the emergency department with nonspecific complaints such as shortness of breath, cough, and hemoptysis, the cause may be due to a disease such as pneumonia, or it may be an indicator of potentially fatal diseases such as pulmonary embolism or foreign body aspiration. In patients who come to the emergency department with pulmonary complaints, the emergency physician should first perform the emergency treatment for the potentially fatal problems of the patients (opening the airway, oxygen support, respiratory stabilization, circulatory stabilization), and make the differential diagnosis of fatal diseases. This book covers the principles of emergency diagnosis and treatment of potentially fatal diseases common in the emergency department. The will be useful for emergency physicians, pulmonologists, intensive care physicians and medical school students.