Alcohol and sleep

You’ve had a hard day. A million things are running through your head as you get ready for bed. You know you’re not going to get to sleep easily. A drink or two will help, won’t it?
Alcohol might help you nod off (as anyone who’s ever passed out after one too many will tell you...), but even just a few drinks can affect the quality of your sleep. And if you regularly drink more than the government's daily unit guidelines of 3-4 units for men (equivalent to a pint and a half of 4% beer) and 2-3 units for women (equivalent to a 175ml glass of 13% wine) you can wake up the next day feeling like you haven’t had any rest at all.

Missing the connection

A recent government poll of 2,000 people found that almost half felt tired the day after drinking more than the daily unit guidelines. However, more than half of those questioned didn’t know that sleep problems could be caused by alcohol.

“A lot of people don’t make the connection between feeling tired and drinking too much,” says Jessica Alexander from the Sleep Council  “Alcohol is one of the ‘three evils’ when it comes to disrupting sleep – the other two being caffeine and smoking.

“If you find yourself regularly drinking above the daily unit guidelines, your body may be constantly trying to catch up and you may not feel fully alert or equipped to deal with the stresses and strains of daily life,” she adds.

The science bit

So why exactly is it that you feel tired after drinking? And why do you wake up so early after a heavy night?

Put simply, alcohol interferes with the normal sleep process. Dr John Shneerson is head of the largest sleep centre in the UK at Papworth Hospital in Cambridge. He explains: “When you drink a lot of 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.

“Your deep sleep is when body restores itself, and alcohol can interfere with this. 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.

Drinking can also mean you have to get up in the night to go to the toilet. And it’s not just the liquid you’ve drunk you’ll be getting rid of. Alcohol is a diuretic, which means it encourages the body to lose extra fluid too, making you dehydrated. Drinking can also cause heartburn, making you wake in the night. It can make you snore more loudly too, because drinking relaxes the muscles in your body. This means the tissue in your throat, mouth and nose is more likely to stop air flowing smoothly, and more likely to vibrate.

Stay within the guidelines

So, all in all drinking can equal a fitful night’s sleep. Keep alcohol to a minimum and you will get better sleep and wake up feeling fresher . You can use our online alcohol unit calculator  to see how many units are in your favourite drinks. And make sure not to drink too close to bedtime, giving your body time to process the alcohol you’ve drunk. On average it takes an hour to ‘metabolise’ one unit, but this can vary widely from person to person. 

How can I get a good night’s sleep?

Here are some more tips from the Sleep Council to make sure you have a restful night:

• Create a soothing environment in your bedroom. Make sure it’s cool and uncluttered, and your bed is comfortable.
  
• Keep regular hours. Going to bed and getting up at roughly the same time, all the time, will programme your body to sleep better.
  
• Stay away from caffeine in the evening. Try a hot milky or herbal drink instead. Other ways you can relax before bed include having a warm bath or listening to some quiet music.
  
• Take exercise to relieve the day’s stresses and strains. But not too close to bedtime or it may keep you awake.
  
• Deal with worries or a heavy workload by making lists of things to be tackled the next day, so they’re not swimming around in your head.
  

Page last updated by

Kate Prior, 31 Jan 2012.

Page checked on

01 Oct 2011