Children: the high incidence age is 4-6 years old, there is no significant difference between male and female gender, mainly due to adenoid tonsillar hyperplasia, daytime sleepiness is not common, the main manifestation is hyperactivity, developmental delay, sleep monitoring shows normal sleep structure, mostly obstructive hypoventilation or periodic obstruction, common treatment: tonsil and adenoidectomy. Adults: the age of onset is usually above 45 years old, more males than females, generally obese, daytime sleepiness is very common, easy to wake up at night, cognitive impairment exists, sleep monitoring shows reduced slow wave sleep and REM phase sleep, mostly periodic obstruction, cortical arousal mostly occurs at the end of most apneas, common treatment is end of breath positive pressure ventilation therapy.