Lung cancer can be detected during medical checkups. Almost all lung cancers can be detected during chest CT examinations, especially some early lung cancers, which are even less than 1 cm in size, can be clearly detected under CT. During lung cancer screening, many other nodules on the lung will be found at the same time. These nodules are not necessarily lung cancer, but they will also be seen during CT, and a general judgment should be made based on the characteristics of the nodules under CT imaging. Based on the characteristics of the nodules, an experienced doctor can basically determine whether it is lung cancer and whether surgery is needed. The final diagnosis of lung cancer is made by pathological examination during surgery, which needs to be noted.