Laryngeal edema is mainly caused by acute infectious diseases of the larynx, surgical injury, allergy, inhalation of chemical gases and other causes. 1. Acute laryngeal infectious diseases: when suffering from acute laryngitis, acute epiglottitis and other diseases, due to inflammation stimulation of the mucous membrane of the larynx appears congestion, edema and other manifestations. Clinical symptoms such as dyspnea and sore throat are common. 2. Surgical injury: if you do surgery on the larynx, neck, trachea and other parts of the body, or do endotracheal intubation, etc., it can cause laryngeal injury, causing laryngeal edema. 3. Allergy: Acute allergic reactions can occur when contacting allergic substances or foods, which can cause congestion and edema of the mucous membrane of the larynx, and may cause obstruction of the airway and respiratory difficulties. 4. Inhalation of chemical gases: If the body is exposed to chemical gases, such as dimethyl sulfate and chlorine, it can cause acute laryngeal edema in the larynx and respiratory difficulties. The occurrence of laryngeal edema needs to go to the hospital in time for examination and treatment, so as not to delay the condition.