1. Symptoms Most of the early patients have no obvious conscious symptoms, or only a slight cough and mild vague pain in the chest. Some patients may show manifestations caused by abnormal secretion of ectopic hormones in the early stage, such as weakness and joint changes. Some patients may have paroxysmal irritating dry cough, or intermittent or persistent blood in sputum, sometimes with more blood and less sputum, and a few patients may have hemoptysis, and some have chest pain or fever of different degrees. Some patients have shortness of breath or difficulty in breathing. The manifestations of patients vary depending on the site of tumor growth and the underlying condition of patients. It should be noted that some patients have no little respiratory symptoms. Lu De, Department of Respiratory Medicine, Shandong Qianfo Mountain Hospital, Shandong Province, China 2. Examination: 1) X-ray examination: X-ray plain film of the chest is an important examination in the diagnosis of lung cancer. It can be used as screening. 2) CT examination: CT examination is largely superior to conventional X-ray examination. It is very necessary for most patients. 3)Magnetic resonance imaging (MRI): The contrast and resolution of MRI is better than CT, and it is easier to identify and clarify the relationship between substantial masses and blood vessels. Cytological examination: 4) Sputum cytological examination: Sputum cytological examination (sputum examination) has been widely used in the diagnosis of lung cancer. Sputum examination does not require expensive equipment, is simple and easy to perform, painless for patients, and has a wide range of application. Sputum examination can also be used for the screening of high-risk groups of lung cancer. 5) Bronchoscopy: Bronchoscopy is an effective means to diagnose lung cancer, which can observe the site and scope of tumor and obtain tissues for pathological examination, and also can speculate the possibility of surgical resection based on the condition of vocal cords, trachea and augmentation. It is very necessary for most patients. 6) Pleural fluid examination: In cases where lung cancer metastasizes to the pleural or pericardial cavity and produces pleural or pericardial fluid, part of the fluid can be extracted and the precipitate can be taken for smear examination after centrifugal processing to find cancer cells for clear diagnosis. 7) Percutaneous puncture lung biopsy: If the mass or infiltrative lesion near the chest wall is suspected to be peripheral lung cancer or diffuse bronchoalveolar carcinoma and the nature of the lesion is not clearly defined by other diagnostic methods, and the patient’s physical condition is not suitable for thoracotomy, percutaneous puncture lung tissue biopsy can be used. 8) Biopsy of metastatic lesions: In advanced lung cancer cases with superficial lymph node metastasis or subcutaneous metastatic nodes in the supraclavicular, cervical and axillary areas, metastatic lesions can be excised for pathological section or smear examination by puncture and extraction of tissues to clarify the diagnosis. 9) Mediastinoscopy: It is mainly used to determine the extent of central lung cancer invading the mediastinum. 10) Thoracotomy: If the nature of the lung mass is not clear after examination by various methods and short-term exploratory treatment, and the possibility of lung cancer cannot be excluded, thoracotomy should be performed if the patient’s general condition permits. If the patient’s general condition permits, he/she should undergo an exploratory thoracotomy. During the operation, according to the lesion and pathological tissue examination results, corresponding treatment should be given. In this way, we can avoid delaying the disease and losing the time of early treatment for lung cancer cases.