Love sputum is due to inflammation that causes more sputum to be produced in the respiratory tract, which causes discomfort such as foreign body sensation and is expelled through coughing, mainly due to acute and chronic inflammation of the respiratory tract: 1. acute respiratory tract infection, due to acute inflammation that causes more mucus to be secreted from the mucous membrane of the respiratory tract, as well as foreign bodies such as bacteria and products and necrotic tissues that stimulate the trachea leading to coughing up sputum. 2. pneumonia, acute and chronic inflammation of the lung tissue also produces large amounts of mucus, bacteria and other foreign substances, and with the airflow as well as the oscillation of respiratory cilia, these inflammatory substances will also form sputum and cough up. 3. chronic bronchitis, in chronic bronchitis, the mucous membrane proliferation is obvious and the secretion is significantly increased, and at the same time, due to the presence of continuous inflammation, it is easy to cause patients to cough and cough repeatedly. 4. bronchial asthma, in acute attacks of asthma, the airway spasm is obvious, and at the same time, the secretion of mucus is increased and the airway sensitivity is increased, and the patient will also experience aggressive cough and sputum symptoms.