Light yellow sputum is usually seen in respiratory tract infections, and the yellow color of the sputum at this time mostly suggests that it is caused by bacterial infections. It is recommended that blood tests, sputum tests, pathogen cultures if necessary, and drug sensitivity tests can be done to select sensitive antibacterial antibiotics for treatment, supplemented by symptomatic treatment. For example, expectorants, cough suppressants and combined nebulized inhalation treatment can be used to eliminate phlegm from the respiratory tract, which can reduce respiratory symptoms, and always adjust according to the test results.