Consuming alcohol before bedtime significantly alters sleep architecture, initia

Consuming alcohol before bedtime significantly alters sleep architecture, initially promoting deeper sleep but later causing disruptions. In the first half of the night, alcohol increases slow-wave sleep (SWS) and suppresses REM sleep. However, as the body metabolizes alcohol, sleep becomes fragmented with more frequent awakenings, especially during the fourth sleep cycle. This leads to decreased sleep efficiency and higher levels of wake after sleep onset (WASO) in the second half of the night. Initial effects: Fewer arousals, less stage one sleep, higher SWS levels Later effects: Increased WASO, lower sleep efficiency, reduced SWS No observed change in sleep cycle length or REM rebound Experts recommend avoiding alcohol at least 3 hours before bedtime