Lung cancer is a primary malignant tumor of the lung, also called bronchial lung cancer, which brings great harm to patients and friends. So, do you know what are the diagnosis methods of lung cancer? Here is a detailed introduction for you. Hemoptysis in lung cancer patients is usually less in quantity, usually blood sputum, which can last for weeks, months or intermittent episodes; chest pain in lung cancer patients is also a common symptom, especially in peripheral lung cancer, chest pain can be the first symptom. The chest pain of lung cancer is often fixed at the lesion site, and in the early stage, it is mostly intermittent and vague, which can be aggravated with position change, deep inspiration and coughing. The above symptoms are important factors for diagnosis of lung cancer, but symptoms alone cannot confirm the diagnosis, and further examination should be done actively when symptoms appear. At present, sputum examination has become an important way for lung cancer screening and diagnosis, and is also the gold standard for lung cancer diagnosis. However, the positive rate of sputum cytology examination for central lung cancer can reach 70-90%, while the positive rate of sputum examination for peripheral lung cancer is only about 50%, therefore, the possibility of lung cancer cannot be excluded for negative sputum cytology examination. (2) X-ray examination of lung cancer: X-ray examination is one of the most common tests for lung cancer diagnosis. The location and size of lung cancer can be understood through X-ray examination. In early stage lung cancer cases, although the mass is not yet visible on X-ray, localized emphysema, pulmonary atelectasis or infiltrative lesions or inflammation in the lung adjacent to the lesion due to bronchial obstruction may be seen. (3) Bronchoscopy: Bronchoscopy is a common method to diagnose lung cancer. Through bronchoscopy, the pathological changes of bronchial lining and lumen can be directly observed, and the site and scope of tumor can be observed. It can also be used to speculate the possibility of surgery based on the condition of vocal cords, trachea and bulge. (4) CT examination for lung cancer: CT examination is largely superior to conventional X-ray examination. (5) Magnetic resonance imaging (MRI): The contrast and resolution of MRI are better than CT, and it is easier to identify and clarify the relationship between substantial masses and blood vessels.