Patients with lung cancer cannot cough up sputum mainly because the sputum is sticky and difficult to be coughed out, probably because the sputum is located deep in the bronchus and it is difficult to be coughed out. Secondly, intravenous use of phlegm-suppressing drugs: intravenous input of phlegm-suppressing drugs, such as Mucosolvan and Bromhexine, can promote the discharge of phlegm. Turning and patting the back: For patients with lung cancer who are bedridden for a long time and have difficulty coughing up phlegm, family members can turn the patient regularly and pat the back from bottom to top to promote the discharge of phlegm. Bronchoscopic aspiration: For lung cancer patients who are comatose or unconscious and have impaired cough reflex or sputum located in deeper parts of bronchus, which is difficult to cough out, fiber bronchoscope aspiration can also be adopted, which means inserting a fiber hose into the lung to suck out sputum. This method requires special equipment and certain techniques and is mainly used for patients in critical condition.