The cause of sputum may be due to smoking, chronic respiratory diseases, etc. When a patient smokes, the toxic and harmful substances in the smoke will enter the respiratory tract and stimulate the mucous membrane of the respiratory tract to produce phlegm, so the symptom of sputum will appear. Old sputum can be seen in chronic diseases of the respiratory system, such as chronic bronchitis, chronic obstructive pulmonary disease, bronchial dilatation, interstitial lung disease and so on. If chronic bronchitis, chronic obstructive pulmonary disease, bronchiectasis and interstitial lung disease are in the stabilized stage, they can be treated with TCM herbal medicine. Commonly, there are cough, white sputum, or sputum with a little foam, this situation is generally the external cold internal drink, to be used to warm the lungs to resolve the drink, cough and phlegm treatment. If coughing up yellowish mucous phlegm, which is thick and not easy to cough up, accompanied by yellow urine, dry stool, red tongue and yellowish greasy moss, use medicines to clear the lungs and dissolve phlegm, such as Thousand Golden Phlegm Soup, Ox-Huang Snake Gallbladder and Sichuan Pei Pui Liquid, Antelope Lung Clearing Pill, which are effective in clearing the lungs and dissolving phlegm. If there is cough, white sticky phlegm and more phlegm, accompanied by chest tightness, loss of appetite and loose stools, use Er Chen Pill and San Zi Nian Zi Tang to strengthen the spleen, resolve phlegm and dry dampness for treatment. If it is Yin deficiency and lung dryness type, such as cough, sputum is not particularly much, or there is a little blood in the stink, accompanied by symptoms of Yin deficiency and lung dryness such as heartburn and fever, hot flashes and night sweating, usually use Sha Shen Maidong Tang to nourish Yin and moisten the lungs, stop cough and resolve phlegm for treatment.