The feeling of neck strangulation is mostly caused by laryngeal edema, which is commonly caused by (1) allergic diseases, such as acute allergy to drugs like penicillin and cephalosporin, and food allergy to alcohol, fish, shrimp and crab. (2) Physical and chemical irritation of the larynx, such as repeated bronchoscopy, corrosive chemical gas inhalation, radiation therapy for laryngeal cancer, etc. (3) Infectious factors, such as parapharyngeal abscessitis, chondromalacia, etc. Acute laryngeal edema develops rapidly and can cause lethal airway obstruction, so tracheal intubation should be performed as early as possible to keep the ventilatory tract open.