There are a few sleep saboteurs or barriers to sleep.  Caffeine, screen time, the wrong kind of exercise at the wrong time and several more…Alcohol is another common “Sleep Saboteur”.  Whilst a nightcap might initially make you feel sleepy and enable sleep, this feeling can wear off during the night because the calming effect on certain brain chemicals will naturally wear off with time.  The brain bounces back which can cause middle of the night wakefulness.  Alcohol also affects blood sugar levels potentially causing a rise in temperature which can cause middle of the night wakefulness.  If you do like a drink and think this might be affecting your sleep, it is probably best to partake several hours before sleep time.