If lung cancer causes dyspnea, the following aspects need to be clarified as soon as possible. 1. whether lung cancer is accompanied by the formation of large amount of pleural effusion, thoracentesis and aspiration should be given to relieve the pressure of lung tissues to relieve dyspnea. 2. If there is a large amount of pleural effusion, closed chest drainage can also be given. 2. Whether lung cancer is accompanied by pneumothorax, if lung cancer tissue rupture causes the formation of pneumothorax, it can also lead to breathlessness, and closed chest drainage is needed as soon as possible to remove excess gas to relieve the compression of lung tissue and promote lung reopening. 3. It is necessary to give pericardial puncture and fluid extraction under ultrasound guidance as soon as possible to relieve the symptoms of heart compression and respiratory difficulty. If lung cancer is similar to asthma attack, croup can be heard in both lungs and dyspnea occurs, active intravenous hormone anti-inflammatory, aminophylline asthma and antispasmodic treatment should be given to relieve clinical symptoms of dyspnea.