Sputum is a secretion from the respiratory tract and is generally present in healthy people. However, if you have respiratory diseases, you will produce a lot of phlegm when infected by disease-causing microorganisms. Chinese medicine classifies phlegm into cold phlegm, wind phlegm, hot phlegm, damp phlegm and dry phlegm, etc. Chronic bronchitis in the elderly starts insidiously, mostly in middle-aged and young people, but also in old age. Patients mostly develop cough and sputum in the cold season, especially in the morning, and the sputum is white mucus foamy. Chronic bronchitis is a chronic non-specific inflammation of the tracheal-bronchial mucosa and surrounding tissues caused by infectious or non-infectious factors. Its pathology is characterized by hyperplasia of bronchial mucus glands and increased mucus secretion. Infection is one of the most important factors in the development of chronic bronchitis. Viral mycoplasma and bacterial infections are the main causes of acute attacks of the disease. Viral infections are common with influenza virus rhinovirus adenovirus and respiratory syncytial virus, bacterial infections are common with Streptococcus pneumoniae Haemophilus influenzae Catarrhella and Staphylococcus, and bacterial infections occur every time secondary to viral or mycoplasma infections on the basis of damaged airway mucosa. . To alleviate the symptoms of coughing foamy mucus phlegm we should develop good habits, especially pay attention not to smoke, people who must work in heavy fumes try to protect themselves, such as wearing a mask, regularly go out to get some fresh air, at least once a year for a check-up, etc.