Chronic bronchitis is a chronic non-specific inflammation of the trachea, bronchial mucosa and surrounding tissues. Clinically, it is characterized by recurrent episodes of cough, sputum or with shortness of breath as the main symptom, lasting for 3 months per year for more than 2 years, excluding other diseases with symptoms of cough, sputum and shortness of breath (such as tuberculosis, pneumoconiosis, lung abscess, heart disease, cardiac insufficiency, bronchiectasis, bronchial asthma, esophageal reflux syndrome and other disorders). Early symptoms are mild and tend to develop in late fall and early spring, with remission in spring and summer. In the late stage, symptoms can be present all year round due to increased inflammation. The pathology is characterized by bronchial glandular hyperplasia and increased mucosal secretion. The disease progresses slowly and is often complicated by obstructive lung disease, and in severe cases, pulmonary hypertension and even pulmonary heart disease and pulmonary encephalopathy often occur, thereby endangering life. The cause of the disease is not completely clear, and may be the result of long-term interaction of a variety of factors; generally divided into exogenous and endogenous causes, exogenous factors include smoking, infectious factors, physical and chemical factors, climate, allergic factors, etc.; endogenous causes are mainly related to the local defense of the respiratory tract and immune function is reduced and autonomic (vegetative) dysfunction. The main reason for this is that it is not possible to get a good idea of what you are looking for. In the viral or viral and mycoplasma mixed infection damage to the airway mucosa based on the secondary bacterial infection. 3, physical and chemical factors: such as irritating fumes, dust, air pollution (such as sulfur dioxide, nitrogen dioxide, chlorine, ozone, etc.) of chronic stimulation, often as one of the triggering factors of chronic bronchitis. Therefore, workers who are exposed to industrial irritant dust and harmful gases have a much higher rate of chronic bronchitis than those who are not exposed to it, and atmospheric pollution is also an important predisposing factor for this disease. 4, climate: cold is often an important cause and trigger of chronic bronchitis attacks, the onset of chronic bronchitis and acute exacerbation is common in the cold winter season, especially when the climate changes suddenly. The cold air stimulates the respiratory tract, in addition to weakening the defense function of the upper respiratory mucosa, but also through the reflex to cause bronchial smooth muscle contraction, mucosal blood circulation disorders and secretion discharge difficulties, etc., conducive to secondary infection. 5, allergic factors: according to the survey, wheezing bronchitis often has a history of allergies. There is a tendency to increase the number of eosinophils and histamine content in the sputum of patients, indicating that some patients are related to allergic factors. Dust, dust mites, bacteria, fungi, parasites, pollen and chemical gases can all be allergic factors and cause disease. 1. Local defense and immune function of the respiratory tract are reduced: the respiratory tract of normal people has perfect defense functions, with the role of filtering, heating and moistening the inhaled air; the mucous cilia of the trachea and bronchial mucosa, as well as the cough reflex, can purify or eliminate foreign bodies and excessive secretions; the fine bronchi and alveoli also secrete immunoglobulins (IgA), which have antiviral and bacterial effects, therefore Under normal conditions, the lower respiratory tract remains sterile. Weakened systemic or respiratory local defenses and immune function can provide intrinsic conditions for the development of chronic bronchitis. The elderly often have a higher prevalence of the disease due to reduced immune function of the respiratory tract, reduced immunoglobulins, degradation of respiratory defenses, and decline in the function of the monocyte-phagocyte system. 2. Phytodysfunction: When the parasympathetic response of the respiratory tract is increased, weak stimuli that do not work in normal people can cause bronchial contraction spasm and increase secretion, resulting in symptoms such as coughing, coughing and shortness of breath. Combined with the above factors, when the body’s resistance is weakened, the airways can develop into chronic bronchitis based on the presence of one or more exogenous factors with varying degrees of sensitivity (susceptibility), which act repeatedly over a long period of time. If long-term smoking damages the respiratory mucosa, coupled with recurrent infection by microorganisms, chronic bronchitis can occur and even develop into chronic obstructive pulmonary emphysema or chronic pulmonary heart disease.