There is no most effective way to resolve phlegm, and it is necessary to treat the causes according to the infectious lung diseases, chronic obstructive pulmonary disease, lung cancer, smoking or environmental stimuli, and to carry out anti-infective, phlegm, anti-tumor and smoking cessation treatments. 1. Infectious lung diseases: mainly include pneumonia, bronchitis, etc. Usually, anti-infectious treatment is needed to reduce sputum secretion fundamentally, and antibiotics such as penicillin, levofloxacin, etc. should be used in accordance with doctor’s instructions. 2. Chronic Obstructive Pulmonary Disease (COPD): The increase in sputum due to the obstruction of ventilation can be treated with aminoglutethimide and other targeted sputum elimination treatments. 3. Lung cancer: it can cause increased sputum, and the basic treatment measures are radiotherapy or surgical resection according to the tumor type and stage, and at the same time, with the symptomatic treatment of sputum transforming drugs such as Ambroxol and acetylcysteine. 4. Smoking or environmental stimulation: prolonged smoking or being under the environment of irritating gases such as oil smoke can also increase sputum, so it is necessary to quit smoking or get out of the environment in time. It is recommended to consult a doctor in time to clarify the cause of the disease and follow the doctor’s instructions to carry out reasonable and standardized treatment.