Laryngeal edema is an infiltration of tissue fluid under the mucosa in the laryngeal laxity. There are two main types of causes: infectious and non-infectious. It is important to take a detailed medical history and perform a laryngeal and systemic examination to identify laryngeal edema as allergic, genetic vascular, or infectious. The former has a history of recurrent episodes of sudden onset with facial swelling and itching. Infectious laryngeal edema can be caused by acute laryngitis, acute epiglottitis, acute laryngeal chondromyelitis, laryngeal abscess, laryngeal tuberculosis, laryngeal syphilis, and other acute purulent inflammatory diseases of the pharynx or neck. Laryngomalacia, hoarseness, laryngeal wheezing and dyspnea may occur within a few hours and may be accompanied by fever and chills, sore throat, and a deep red edema and shiny surface of the mucosa visible on laryngoscopy. Non-infectious laryngeal edema can be caused by heart disease, nephritis, liver cirrhosis, hypothyroidism, etc. Allergic and genetic vascular diseases are particularly rapid in onset and development, patients often have laryngeal wheezing, hoarseness, dyspnea, or even asphyxia within a few minutes, and laryngoscopy shows diffuse edema and pale laryngeal mucosa. 1, metaplastic laryngeal edema: laryngoscopy shows pale, edematous laryngeal mucosa with plasmacytic exudate on the surface. In severe cases, vocal cord movement is impaired and the trigeminal sign appears. Pay attention to the differentiation with infectious laryngeal edema. 2, hereditary angioneurotic laryngeal edema: laryngoscopic examination shows pale, edematous laryngeal mucosa with plasmacytic exudate on the surface, which may involve the tongue, palatal lobe and soft palate. In severe cases, the vocal cord movement is impaired and the trigeminal sign appears.