what aspect of sleep does alcohol negatively impact?

Alcohol negatively impacts several aspects of sleep, primarily by reducing the quality of sleep through disruption of the sleep cycle. It specifically decreases the amount of restorative rapid eye movement (REM) sleep, which is crucial for healing, memory retention, and feeling rested. Alcohol also causes shorter sleep duration, more frequent awakenings, and fragmented sleep. Additionally, it disrupts circadian rhythms and can worsen sleep disorders such as sleep apnea. While alcohol initially helps with falling asleep due to its sedative effects, it results in poorer quality sleep overall and may cause insomnia and excessive tiredness the next day.