Chronic bronchitis is a chronic non-specific inflammation of the mucosa of the trachea, bronchial tubes and their surrounding tissues, which is mainly characterized by coughing, coughing up sputum with or without wheezing, and its diagnostic criteria are mainly based on clinical symptoms. The diagnostic criteria of chronic bronchitis are coughing, coughing up sputum or accompanied by wheezing, the onset of the disease lasts for three months or more each year for two or more years, and various other chronic diseases causing similar symptoms can be ruled out, such as asthma, pulmonary tuberculosis, bronchiectasis, and cardiac insufficiency. In addition to this, the diagnosis of chronic bronchitis can be combined with other laboratory tests. For example, X-ray examination reveals thickening and disorganization of the lung texture, showing speckled, reticular and striated shadows, especially the lung base is more obvious; if the lung function suggests small airway obstruction, the maximum expiratory flow rate-volume curve in 75% and 50% lung capacity when the flow rate is significantly reduced. For patients who suspect chronic bronchitis, it is recommended to consult a doctor in time, make a clear diagnosis under the guidance of the doctor and actively cooperate with the treatment.