Because the symptoms of lung cancer are not significant at the beginning of the disease, by the time there are significant signs, the disease is already in the middle and late stages, and it is not easy to treat. However, different patients may have different symptoms because of their different bodies. According to the statistics, the current resection rate of lung cancer surgery in China is 85%-97%, and the mortality rate of 30 days after surgery is less than 2%. The overall 5-year survival rate is 30%-40%. 2.Small cell carcinoma (undifferentiated small cell carcinoma) has a younger age of onset and generally originates from the larger bronchial tubes, mostly central type lung cancer (i.e. near the entrance and exit of large blood vessels, nerves and other structures in the lung, which is called pulmonary hilar), small cell carcinoma has a higher malignancy, faster growth rate, and generally appears early with lymphatic or (and) bloodstream extensive metastasis. In addition to the early and middle stage symptoms (irritating cough, bloody sputum, chest tightness, chest pain, wheezing, shortness of breath, fever, etc.), there are also signs of lung cancer invasion, compression of adjacent tissues or (and) organs and distant metastasis, as described below: 1. compression or invasion of phrenic nerve with ipsilateral paralysis at all levels. 2. Vocal cord paralysis and hoarseness due to compression or invasion of the recurrent laryngeal nerve. 3, compression of the superior vena cava causes facial, neck, upper extremity, chest venous anger, subcutaneous tissue edema, and upper extremity venous pressure ascending. 4.Invasion of pleura causes pleural effusion, which is often bloody; shortness of breath can be caused by large amount of effusion; the dominant cancer invading the pleura or pleural wall can cause severe chest pain. 5.Cancer invading or (and) compressing mediastinum and esophagus can cause dysphagia. 6.Lung cancer at the top of upper lobe may invade mediastinum and compress tissues and organs above the thoracic opening, such as the first rib, subclavian artery and vein, brachial plexus nerve, cervical sympathetic nerve, residual severe chest and shoulder pain, upper limb venous anger, edema, arm pain, upper limb movement disorder, ipsilateral upper eyelid ptosis, pupil narrowing, eye entropion, facial sweating and other transsympathetic syndrome.