The trick of coughing up phlegm is false. There are no tricks for coughing up sputum. Lung function exercises and treatment for dissolving mucous phlegm need to be carried out according to the cause of the disease, such as poor lung function due to underlying lung diseases and sticky sputum due to chronic obstructive pulmonary disease respectively. 1. Coughing up sputum requires the lungs to inhale enough air for a short period of time to carry the sputum out through the airflow. Therefore, it is relatively difficult for people with underlying lung diseases or poor lung function to cough up sputum, and they need to exercise their lung function through sports. At the same time, some people do not have the habit of coughing up sputum, resulting in difficulty in coughing up sputum, and need to be targeted exercise. 2. In addition, if it is difficult to cough up the sputum due to the viscous sputum of COPD, it can be combined with medication to dissolve the viscous sputum, such as acetylcysteine effervescent tablets, etc. By diluting the sputum, the sputum will be dissolved. By diluting the phlegm, it makes it easier to cough up, and improves symptoms such as impaired lung ventilation. It is recommended to seek medical advice and use medication under the guidance of a doctor.