The appearance of yellow sputum from coughing up indicates the occurrence of purulent infection, which is caused by bacteria. At this time, bacteria erode the respiratory system, and the cells of the respiratory mucosa will secrete a large amount of inflammatory exudate, and the neutrophils and phagocytes in the body will gather at the inflammation site to devour these foreign bacteria, and these cells will then shed and necrosis, and mix with the secreted inflammatory exudate to form yellow sputum, which is often accompanied by the lysis of neutrophils and requires the use of antibiotics The effect is still better. If there is no allergy to penicillin, for respiratory infections, amoxicillin or amoxicillin clavulanate potassium can be used. If there is also no allergy to cephalosporin antibiotics, cefixime, cefradine or cefadroxil can be used for anti-inflammatory treatment. In addition, if there is an allergy to all of the above drugs, azithromycin can be used for alternative treatment.