Effect and mechanism of cangma Pill on airway mucus hypersecretion in patients with stable bronchiectasis based on NE / EGFR / MUC5AC pathway

INTERVENTION: Intervention group:cangma pill;control group:Carbocysteine; CONDITION: Respiratory infectious diseases PRIMARY OUTCOME: CASA_Q;Sputum volume; SECONDARY OUTCOME: The number of acute exacerbations within 3 months of follow‐up;Physical and chemical properties of sputum: ratio of dry/wet weight of sputum.;Decline rate of FEV1 in lung function;VAS scores; INCLUSION CRITERIA: The diagnostic standard of dampness syndrome of spleen deficiency is made by referring to the Chinese Medicine Industry standard of the People's Republic of China‐Chinese Medicine Syndrome Diagnosis Standard: wheezing cough and chest tightness, sputum is easy to cough, sputum is sticky or spit is not comfortable, the chest is stuffy, the mouth is greasy, stomach cavity and abdominal distension. The tongue is pale, the tongue coating is white and greasy, the pulse string is slippery. Inclusion criteria 1) Patients with stable bronchiectasis diagnosed which conforms to the western medicine and airway mucus hyper‐secretion assessment; 2) Patients with bronchiectasis presented as syndrome of spleen deficiency and dampness in Chinese medicine; 3) Aged between 18 and 80 years old; 4) Able to understand and sign the informed consent.