At present, the pathogenesis of lung cancer is not yet clear, but its high-risk factors are as follows: 1. smoking factor: the incidence of lung cancer among smokers is more than 10 times that of non-smokers; 2. environmental pollution: environmental pollution can lead to higher incidence of lung cancer; 3. occupational factors: asbestos can lead to lung cancer, and occupations with more exposure to asbestos have higher risk of lung cancer; 4. dietary factors: unhealthy diet and work and rest habits are also important causative factors of lung cancer; 5. chronic lung diseases: patients with underlying lung diseases can lead to lung cancer; 6. genetic factors: patients with genetic factors can have significantly higher incidence.