How alcohol affects your sleep patternsEven a couple of drinks can interfere with the normal sleep process. When you drink alcohol close to bedtime, you can go straight into deep sleep, missing out on the usual first stage of sleep, called rapid eye movement (REM) sleep."Deep sleep is when the body restores itself, and alcohol can interfere with this," explains Dr John Shneerson, head of the sleep centre at Papworth Hospital in Cambridge. "As the alcohol starts to wear off, your body can come out of deep sleep and back into REM sleep, which is much easier to wake from. That's why you often wake up after just a few hours sleep when you've been drinking."In the course of a night you usually have six to seven cycles of REM sleep, which leaves you feeling refreshed. However, if you've been drinking you'll typically have only one to two, meaning you can wake feeling exhausted.