Alcohol helps you fall asleep, then wrecks the second half of the night.
Drinkaware says alcohol reduces time in REM sleep, so you wake unrefreshed, and that even a couple of drinks has the effect. The NIAAA notes people fall asleep faster after drinking but their sleep is fragmented and they wake earlier, with toilet trips from alcohol's diuretic effect adding to it. Snoring and sleep apnoea also worsen. The practical fix is timing: stop a few hours before bed, alternate with water, and keep the dose small. Needing a drink to fall asleep is its own warning sign.
What to do
Common questions
Why do I sleep badly after drinking?
Alcohol is a sedative that betrays you halfway through the night. It does help you fall asleep faster, but as your body metabolizes it, the second half of the night fills with lighter, broken sleep. Drinkaware explains that alcohol in your system cuts the time you spend in REM sleep, the mentally restorative stage, so you wake feeling unrefreshed, and notes that even just a couple of drinks has this effect. The NIAAA adds that people tend to wake up earlier after drinking, and that alcohol's diuretic effect sends you to the toilet during the night, adding dehydration to the disruption. Alcohol also relaxes throat muscles, making snoring and any sleep apnoea worse. The fix is timing more than abstinence: stop drinking at least a few hours before bed so most of the alcohol clears before you lie down, drink water alongside, and keep the count low, because dose is everything here. If you rely on a drink to fall asleep, that is worth noticing, since tolerance builds and the sleep gets worse, not better; the NHS insomnia page has better tools, and your GP can help with both the sleep and the drinking pattern.