How Does Alcohol Affect Sleep Quality?

Unless you’ve been asleep, you’ll know long term excessive drinking is bad for the body. It’s linked to depression, liver failure, heart disease, and some cancers. But even at the less excessive end of the scale, drinking is still a fact of life in many cultures. The average person is bound to hit the hay under the influence of alcohol at some point.

So what effects does this prevalent substance have on one night’s sleep exactly?


You’ll be sedated, but not strictly asleep

Neuroscientist and author of ‘Why We Sleep’ Matthew Walker is quick to point out that alcohol is a sedative, and sedation is not the same as sleep.

When we have a drink before bed, we can feel drowsy and drift off much easier. But this ‘drifting off’ is merely the sedative properties ‘knocking out’ the central cortex in our brain. We look asleep, but in the first half of the night, our bodies won’t be spending as much time in each of the 5 sleep stages as normal.

You’re more likely to snore

The sedative effect of alcohol will also relax the muscles in your body more than usual during sleep. That extra relaxation can cause the muscles around your jaw and throat to collapse in a way that restricts your airways. So you’re more likely to snore.

In extreme cases, it can even cause sleep apnea – a sleep disorder where breathing stops and starts during the night. If you already suffer from snoring or sleep apnea, expect these to be exacerbated by alcohol.

You won’t remember it, but your sleep will be fragmented

Alcohol, like caffeine, blocks adenosine – a hormone that causes sleepiness. Consequently, your sleep can be littered with many awakenings throughout the night. These awakenings stop you from feeling fully refreshed in the morning. However, they are very minimal, sometimes lasting only a few seconds, so you’re unlikely to recall them. But from your perspective, you’ll have slept through the whole night so you’re left confused about why you feel awful in the morning.

You’ll lose vital REM sleep

Alcohol is very effective at blocking rapid-eye-movement (REM) sleep too. This dream sleep stage is vital for many things including our emotional and mental health. Just how vital dream sleep is for our health was proved in a 1980s study that showed rats can die from REM sleep deprivation almost as fast as they would from food deprivation.

You’ll definitely get up to pee

No one needs a reminder of alcohol’s diuretic effects. But consider that when you drink before bed, those effects take hold whether you’re awake or not. So you might not make it to morning without a trip to the loo, ruining what should be a long stretch of sleep.

So, should you drink before bed?

The final decision is always up to you. But the main thing to take away is that although on the surface it feels like alcohol makes us sleep better, that’s not the case under the bonnet. It’s more likely damaging the quantity and quality of your sleep. If you do this regularly over time, it can lead to chronic sleep deprivation that may damage sleeping habits permanently.

In the end, common sense wins again in relation to alcohol: enjoy it now and again, but if you want minimal sleep disruption, don’t make it a bedfellow.

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