Coughing up phlegm in winter may be caused by diseases such as allergic asthma, pneumonia, chronic bronchitis and chronic obstructive pulmonary disease. In this case, general treatment and medication can be used to alleviate the symptoms of coughing and phlegm. 1. General treatment (1) Allergic asthma: Avoid contact with allergens such as cold air and haze, and strengthen protective measures such as wearing a mask to protect the airways. (2) Pneumonia: Patients should pay attention to a light diet and avoid spicy and stimulating foods. Drink more water to promote the dilution of sputum, thus accelerating its discharge. (3) Chronic bronchitis and chronic obstructive pulmonary disease (COPD): quit smoking, wear a mask when going out, and wash hands frequently to prevent infection. 2.Drug treatment (1) Allergic asthma: apply glucocorticosteroids combined with β2 agonists such as budesonide formoterol for inhalation and leukotriene receptor antagonists such as montelukast, and for those with a lot of phlegm, combine with phlegm-cleansing drugs such as aminoglutethimide tablets. (2) Pneumonia: anti-infective drugs such as levofloxacin and cefaclor can be taken; nebulized inhalation of phlegm removing drugs such as acetylcysteine can be used; cough suppressants such as compound licorice tablets can be used to relieve the symptoms. (3) Chronic bronchitis, chronic obstructive pulmonary disease: if combined with bacterial infection, antibiotics such as roxithromycin, cefuroxime can be taken to fight infection. Use of cough-relieving and expectorant drugs such as compound licorice syrup, aminoglutethimide and so on. Patients with chronic obstructive pulmonary disease can use bronchodilators such as tiotropium bromide inhaler, budesonide formoterol for inhalation. Patients should go to the hospital as soon as possible to clarify the cause of the disease. The above mentioned drugs should be taken under the guidance of a doctor.