Particularly thick sputum may be associated with pneumonia, acute exacerbation of chronic bronchitis, bronchiectasis combined with infection, and other causes. 1. Pneumonia: due to the propagation of pathogens in the lungs, resulting in congestion and edema of lung tissues, releasing a lot of inflammatory mediators. And activate the body’s immune system, mobilize a large number of white blood cells to phagocytosis of pathogenic microorganisms after death, will cough a lot of thick sputum. 2. Acute exacerbation of chronic bronchitis: due to the persistent chronic irritation in the airways, there will be coughing sputum. During acute exacerbation, pathogens proliferate and stimulate the mucosa to produce large amounts of secretions, which also results in large amounts of thick sputum. 3. Bronchodilatation combined with infection: because of purulent inflammation of the bronchial tubes and fibrosis, the patient will cough up a large amount of yellow sputum, and there may also be fever, hemoptysis and other symptoms. Thick sputum is more, may also be related to other diseases, it is recommended to go to the hospital in time, to clarify the cause, follow the doctor’s advice and timely treatment.