Sleep apnea syndrome (SAS) refers to the cessation of airflow from the mouth or nasal cavity for more than 10 seconds and more than 30 times within 7 hours of sleep at night. Common causes include nasal septum deviation, nasal polyps, nasopharyngeal adenoids hypertrophy, macroglossia, tonsil hypertrophy, mandibular deformity, chronic obstructive pulmonary disease, cor pulmonale, obesity dyspnea and hypersomnia syndrome, acromegaly, myxedema, high altitude polycythemia, drug-induced respiratory depression, polio bulbar inflammation, etc. Apnea can be divided into central type (no breathing action of the chest and abdominal muscles), obstructive type (the chest and abdominal muscles try their best to make breathing action) and mixed type (the chest and abdominal muscles have no breathing action at the beginning, and then appear and gradually strengthen), during which there is no spontaneous breathing.