I. What are the common manifestations of lung cancer? Clinical manifestations, typical symptoms are cough, sputum and hemoptysis. There are also a considerable proportion of patients who do not have any symptoms but are only found in chest X-ray and CT examination. The manifestations of invasion to adjacent organs, such as hoarseness, chest tightness, shortness of breath, fever and chest pain. Clinical examination may reveal diaphragmatic paralysis, facial swelling due to superior vena cava obstruction, jugular vein anger, and hemorrhagic pleural fluid. Apical lung tumors (Pancoast tumor or supraglottic sulcus tumor) may cause brachial plexus palsy and cervical sympathetic nerve syndrome. In addition, a few lung cancers may produce endocrine substances, which may cause extra-pulmonary manifestations, such as osteoarthritis syndrome (pestle and mortar finger, arthralgia, periosteal hyperplasia, etc.) Cushing syndrome, myasthenia gravis, male breast enlargement, multiple muscle neuralgia, etc. What tests should be done to diagnose lung cancer? 1.Imaging examination: such as chest X-ray, chest CT, PET/CT, etc. They are used to locate the tumor and determine the benignity and malignancy from imaging. 2.The diagnosis of lung cancer requires cytological or histological evidence, sputum examination of cancer cells, fiberoptic bronchoscopy, for central tumor, direct observation of lesion, biopsy and smear examination of bronchial secretion can be taken at the same time; for peripheral tumor, percutaneous tumor aspiration biopsy is feasible; for superficial lymph node metastasis, aspiration or biopsy is the simplest and most effective method to confirm; ultrasound biopsy under fiberoptic microscope (EBUS) The biopsy of enlarged mediastinal lymph nodes is the latest technique, and the pathological diagnosis can be obtained for tumors between the central and peripheral types. 3. The examination of tumor markers has important reference value for the diagnosis of lung cancer.