Chronic bronchitis is a common and frequent disease of the respiratory tract, with long-term coughing, coughing or wheezing as the main clinical features, easily affected by a variety of factors and acute attacks. What are the complications of chronic bronchitis? The following is a detailed description of the following: 1. Obstructive emphysema is the most common complication of chronic bronchitis, patients with diffuse hyperplasia of the alveolar wall fibrous tissue. In addition to luminal narrowing and sputum obstruction, expiration is not smooth, so obstructive emphysema can occur. 2. Bronchopneumonia Chronic bronchial inflammation spreads into the peribronchial lung tissue, and patients have chills, fever, increased cough, increased sputum, and purulent sputum. On X-ray, there are speckled or small patchy shadows in both lower lung fields. 3, bronchial dilatation Chronic bronchitis with repeated attacks, bronchial mucosa congestion, edema, formation of ulcers, hyperplasia of fibrous tissue in the wall, more or less deformation of the lumen, dilatation or narrowing. The dilated part is mostly columnar in change. The bronchial dilatation formed after whooping cough, measles or pneumonia is often columnar or cystic in shape and is more severe than that caused by chronic bronchitis. In addition, there are viruses that play an important role in the development and progression of the disease. The viruses isolated during the acute exacerbation of chronic bronchitis are rhinovirus, influenza B virus, parainfluenza virus, mucovirus, adenovirus, and respiratory syncytial virus. Viral infection causes damage to the respiratory epithelium, which favors bacterial infection and causes the onset and recurrence of the disease.