Yellow particles in white sputum may be caused by combined bacterial infections, inhalation infections, external drainage of lung foci, tonsil stones and other diseases. 1. Combined bacterial infections: upper respiratory tract infections caused by viral infections, usually the clinical symptoms will not be too significant, can be manifested as coughing, coughing sticky white sputum and so on. With the aggravation of inflammation, the body’s immunity is further reduced, susceptible to suppurative bacterial infections, the airway mucosa can ooze yellow purulent secretions, which is manifested in white sputum containing yellow particles. 2. Inhalation infection: Inhalation of foreign matter, foreign matter into the respiratory tract, can be adhered to the posterior wall of the respiratory tract, through the mucus wrapped in the sputum can be coughed up with the movement of the cilia discharged, can be manifested as white sputum with yellow particles. 3. Lung foci excretion: lung previous anaerobic bacterial or bacterial infections, due to anaerobic metabolism can produce necrotic material, through coughing and ciliary movement out of the body, can be white sputum with yellow granular material. 4. Tonsil stones: long-term chronic inflammation of the tonsils can cause local tissue adhesions, calcium salts, food residues, bacteria, mucus and other deposits in the crypt mouth, forming yellow stone-like particles, can be discharged with the sputum when stimulated by coughing. Yellow particles in white sputum should be treated promptly by a doctor, and appropriate treatment under the guidance of a specialist will help to alleviate the uncomfortable symptoms as soon as possible.