Coughing phlegm out of the lungs can be done by active anti-infection, deep breathing, patting the back and dissolving mucous phlegm. 1. Generally when there is a respiratory tract infection, the phlegm will be more, when it is clear that there is an infection, need to actively anti-infective treatment, can effectively reduce the phlegm. 2. Deep breathing, through deep breathing, exercise the respiratory muscle strength, can let the cough produce greater airflow, so as to bring out the deep phlegm, is an effective way to cough out the deep phlegm. 3. Patting the back, making a hollow shape with both hands, repeatedly patting the back from bottom to top to help the mucous phlegm attached to the trachea and bronchial tubes to fall off, and gradually coughing out the phlegm, which is an effective solution for the elderly and other groups who have difficulty in coughing up phlegm. 4. To dissolve mucous phlegm, drugs such as acetylcysteine effervescent tablets and carbocysteine can be used to reduce the concentration of phlegm so that it can be coughed up and absorbed more easily, but the use of drugs needs to be in accordance with medical advice. If the sputum is thick and sticky, it is recommended to consult a doctor and follow the doctor’s instructions. The above medications should be used under the supervision of a physician.