If lung cancer patients have cough symptoms after radiotherapy, first of all, several causes of cough should be distinguished: 1.If it is lung infection, lung infection is confirmed by imaging, by sputum bacteriological culture, and by blood calcitoninogen. If it is caused by infection, most of them can be effectively relieved through anti-infection, sputum drainage, and symptomatic treatment. 2. Radiation airway infection and radiation pneumonia caused by radiotherapy, which are usually caused by irritating dry cough, usually without sputum, can be symptomatically treated through systemic application of glucocorticoids and local nebulized inhalation after bacterial infection is excluded through auxiliary examination. The vast majority of patients can be effectively controlled; 3. Tumors invade the bronchi, that is, there is a foreign body in the bronchi, and this irritant cough does not have a lot of sputum, but those caused by tumors may need to resort to codeine. This kind of drugs and sedative drugs may be needed to stop coughing. 4. Another situation is tumor progression, for example, some patients have malignant pleural effusion and pericardial effusion during the treatment period when the tumor progresses rapidly. Imaging is good to identify. If this situation occurs, it is necessary to change the treatment strategy and carry out system planning again, but of course this situation is generally rare.