NREM Stage 3, accounting for 15-25% of total sleep, is the deepest of all sleep stages. This stage contains primarily [[Wikipedia:delta waves|delta waves]], which are high-amplitude and low-frequency. Hence, this stage is also known as slow-wave sleep (SWS). It is very difficult to wake up from this stage; attempts at doing so tend to result in [[Special:MyLanguage/sleep inertia|sleep inertia]] -- a period of intense grogginess and impaired cognitive function. This stage of sleep plays a critical role in the maintenance of the brain through the [[Wikipedia:Glymphatic system|glymphatic system]]. This process takes about 30 to 60 minutes of continuous NREM3 to complete, and could be hindered by schedules containing only short naps.
NREM第三階段佔總睡眠的15至25%,是所有睡眠階段中最深的階段。這個階段主要包含高振幅和低頻率的Delta波。因此,它也被稱為慢波睡眠(SWS)。要從這個階段中醒來是非常困難的。試圖這樣做往往會導致一段強烈的呆滯和認知功能受損的時期——睡眠惰性。NREM3通過淋巴系統在維護大腦方面發揮著關鍵作用。這過程需要約30至60分鐘的連續的NREM3才能完成,因此只包含短暫小睡的時程可能會阻礙到此功能。