There are many reasons for coughing up green sputum, which is commonly caused by Pseudomonas aeruginosa infection and bronchial dilatation. 1. Pseudomonas aeruginosa infection: When Pseudomonas aeruginosa is infected, it produces a variety of toxic substances, causing necrosis and shedding of human tissues and the formation of green sputum. It can be treated with a combination of bacteria-sensitive antibiotics, such as piperacillin and gentamicin, and if there is a cough, it can be treated with medicines such as compound licorice combination orally. 2. Bronchial dilatation: when Staphylococcus aureus, Pseudomonas aeruginosa and other infections, bacterial toxicity is relatively strong, when they spread to the respiratory mucosa, the body’s self-defense mechanism will phagocytosis parcel, kill cellular viruses, with sputum discharged, generally yellow-green sputum. Coughing up green sputum may also be caused by other reasons, it is recommended that the patient consult a doctor in a timely manner to clarify the cause of the disease, under the guidance of the doctor for treatment. The above medicines are for reference only, follow the doctor’s instructions for medication.