Snoring in sleep is commonly referred to as snoring. The main etiology is due to the narrowing or blockage of the anatomical part of the upper respiratory tract, which can lead to the occurrence of snoring. The first point is pharyngeal lesions, nostril stenosis or atresia, nasal polyps in the deviated septum, hypertrophic rhinitis, and allergic rhinitis. Nasopharyngitis, inflammatory pharyngeal tumor, pharyngeal machine paralysis, epiglottic cyst, epiglottic tumor and other diseases can cause snoring. The second point is oral lesions. Tongue lesions are more serious, such as megalingualism, tongue tumor, etc. The third point is some congenital facial developmental malformations. For example, Down syndrome has a low nasal bridge, small rounded lower collar, high waist arch, and mental retardation. There is also Prader-Willi syndrome, which is characterized by dysphagia, obesity, facial deformity, and mental retardation. The fourth point is to consider systemic diseases, acromegaly can cause enlarged tongue, hypothyroidism leading to mucinous edema, chronic lymphocytic leukemic pharyngitis, etc., which can cause snoring.