Phlegm sounds, which should be referred to as sputum sounds, are not usually produced by breathing in patients with laryngitis. The sputum sound is a friction sound caused by increased secretion and gas flow, which occurs mainly in the trachea and bronchial tubes. After the trachea and bronchial tubes are infected and chemically stimulated, the mucous membrane of the airways will thicken and edema, and secretions will increase, causing localized friction and phlegm sounds when gas flows through during breathing. Inflammation of the pharynx usually does not cause symptoms, mainly manifested as dry throat, sore throat, pharyngeal foreign body sensation, some will have symptoms of stridor. If the phlegm sound is accompanied by coughing and does not get better, it is necessary to consult a doctor in time to clarify the cause and diagnosis, and standardize the treatment under the guidance of a physician to avoid delaying the condition.