Lung cancer is the most prevalent malignant tumor in China, and smoking is one of the most important factors leading to lung cancer. Family Doctor Online recently conducted a survey on “Smoking and Lung Health”. According to the survey, more than half of the participants were unaware that lung nodules found during medical examinations could be early-stage lung cancer. When a lung nodule is detected on CT, the nature of the nodule can be clearly diagnosed through bronchoscopy, navigational bronchoscopy biopsy, sputum cytology, and blood tumor markers. Researchers recommend annual low-dose spiral CT lung screening for people at high risk of lung cancer, which is a means of lower radiation dose and can detect small lesions that cannot be revealed by ordinary chest X-ray. Of course, the prevention and treatment of lung cancer should be multi-faceted, not only by quitting smoking, but also by reducing exposure to five types of “gases” (smoke, outdoor air pollution, kitchen fumes, bad indoor air, and anger), improving one’s lifestyle, improving occupational causative factors, and enhancing lung cancer screening.