The difference between bronchitis and bronchiectasis is mainly that: 1. The two concepts are not the same. Bronchitis is an inflammation that occurs in the bronchial mucosa and its surrounding tissues, including both acute inflammation and chronic inflammation, while fine bronchitis is an inflammation that occurs in the fine bronchi and is mostly acute. 2. There are differences in the age of occurrence. Bronchitis can occur in both children and young people, as well as in the elderly; while fine bronchitis occurs in infants and children within two years of age. The scope of lesions involved is not the same. The lesions of bronchitis are mostly confined to the bronchi, while the lesions of bronchitis occur in the fine bronchi and can also involve the bronchi and alveoli. 4. The clinical symptoms are different. Acute bronchitis is characterized by fever, cough and sputum, while chronic bronchitis is characterized by recurrent cough, sputum or chest tightness and wheezing. Fine bronchitis starts with obvious cough and wheezing symptoms, accompanied by accelerated respiratory rate, and most of them are accompanied by obvious triple concave signs.