You’ve probably noticed that drinking beer, wine or spirits helps you fall asleep. But it may come as a surprise to you that drinking to help you go to bed isn’t a good idea. So, to help clear things up, we answer the question, “how does alcohol affect sleep?”
Below we go through the things that happen when you drink alcoholic beverages right before or near bedtime. And, in the process, explain all the things that it does to your body while you’re asleep to help you decide whether or not it’s something for you.
What Happens When You Drink Before Bed?
Alcohol helps you fall sleep
If you have ever had a hard time falling asleep then you know how stressful it can be. But, reaching for that bedtime drink will help you fall asleep quicker (1).
During the first half of your sleep cycle you will experience a deeper more restorative sleep. Drinking a little bit of alcohol before bed will keep you in non-REM stage three and stage four sleep for longer. This allows for your body to repair tissues, build bones, and strengthen the immune system for a longer period (1).
And, these restorative effects in slow-wave sleep are especially important when your body is processing alcohol which may be why you end up spending more time in this stage.
It increases deep sleep
The increase in slow wave sleep when you consume alcoholic beverages before bed is notable during the first half of the night, according to a study. More importantly, its effects happen whether you had one drink or several (4).
While it appears from this study and other similar experiments that alcohol increases deep sleep for the first few hours in all individuals, it is important to note that this trend may not be observable in heavy drinkers or alcoholics (4).
That’s because there hasn’t been research done on the sleep patterns of alcoholics. So, it is unknown if they experience the same increases in stage three and stage four deep sleep throughout the night.
But, if they do, it probably is not a drastic increase in deep sleep like what occasional and social drinkers experience.
Alcohol reduces REM sleep
While alcoholic beverages can help you drift off to sleep quicker, they also cause a drastic decrease to the amount of REM sleep you will get when you fall asleep shortly after having a drink (1). This decrease in REM sleep comes from an increase in disruptions during the second half of sleep.
The major sleep disruptions to REM sleep offset the advantages of falling asleep faster during the first half of sleep. That’s because shortened REM sleep cause a less restful sleeping experience that can negatively impact cognition and memory.
And, these effects are severely worsened at moderate to high doses of alcohol prior to bedtime (1).
So, if you need a night cap to fall asleep faster, a glass of wine is the way to go. That’s because it will only impact REM sleep slightly. But, drinking too much will drastically reduce the REM sleep and its restorative effects.
Should you consume alcohol along with sleeping pills?
While sleeping pills can be a great tool to help you fall asleep sooner and stay asleep longer, they aren’t always a good idea. This is especially true when you think of mixing them with alcohol.
When the warnings against consuming alcohol along with a sleep aide is ignored, the result can be dangerous and deadly (6).
Drinking alcohol increases deep sleep. The problem with that is so do sleeping pills. Together, they double the effects which can cause your heart rate and respiration rate to drastically slow or stop completely (6).
Not only can these effects occur but combining a depressant like alcohol with a sedative like Ambien will result in an overdose. The reason is that both magnify one another. As such, it can kill you if you do not get help (6).
Unfortunately, individuals suffering from drug or alcohol addiction are prone to making risky drug combinations like this. They do so in order to bump the effects of what they are taking.
That said, sleeping in this state is dangerous. So, any combination involving sleep aids and alcohol should be avoided no matter how hard it is to fall asleep.
You’ll feel tired and irritable the next day
Whether you wake up from a night of drinking feeling hungover or refreshed and ready to run, drinking can have a significant impact on your mood (8).
This effect is more pronounced in individuals who are suffering from a mood disorder or have anxiety about their behavior the night before when their inhibitions were lowered.
Sometimes this tired, irritable feeling can come on seemingly without any reason at all. And, you won’t be sure why you feel like this.
But, there is a biological reason we are more irritable after a night of drinking. That’s because inflammatory hormones and chemicals increase and your blood sugar drops as your body focuses on excreting the alcohol from your system (8). The lower blood sugar and increased inflammatory compounds can leaving you feeling exhausted and irritated.
How Alcohol Affects Your Sleep
You’ll wake up in the middle of the night
If you wake up in the middle of the night after having a few drinks, then you don’t have to blame it on a weird dream you can’t remember. Instead, you can attribute it to the alcohol (9).
As we mentioned previously, alcohol can help you fall asleep faster. It also lets you get more stage three and stage four deep sleep during the first half of your slumber.
Your body processes most of the alcohol you consume during the restorative stages of sleep. But, you’ll wake up after it is finished. Sometime, you’ll also find it hard to get back to sleep (9).
While more research needs to be done to explain the exact reasoning behind this, researchers believe it is because brain chemicals that help you wake up are stimulated after your body processes all the alcohol you consumed.
So, if you are tired of sleep interruptions, skip on that extra glass of wine before bed.
Alcohol helps you fall asleep quicker because of its depressant effects. But, the increase in deep sleep isn’t productive, especially if you are an individual prone to snoring (10).
Even if you aren’t normally a loud sleeper, alcohol consumption causes your throat muscles to relax more than they normally would during sleep.
When your throat muscles relax, the oropharynx folds slightly. And, it is this collapse that results in snoring.
That said, snoring can cause you to wake up with a dry throat, sore throat, or a grouchy bed partner. So, if this sounds like you skip on the brews before bed.
You may experience night sweats
Alcohol consumption and sleep deprivation for individuals who drink regularly can drastically increase the occurrence and duration of night sweats (2).
That’s because consuming alcohol increases your heart rate, dilates blood vessels, and has other significant effects on your central nervous system and circulatory system.
The changes that alcohol causes induce sweating. This is especially true when you are sleeping after having a few too many drinks (2).
While only 10% of the alcohol you consume is excreted through urine and perspiration, alcohol still stimulates your body to trigger night sweats as a means of processing and removing alcohol from your system sooner.
Finally, it’s also worth noting that if you are currently suffering from fever, menopause, or taking medications your night sweats induced by alcohol, you may be prone to more severe sweating compared to individuals who are not predisposed to night sweats.
Insomnia is a sleep disorder that steals sleep away from thousands of people worldwide. And, there are some treatments to help overcome these issues. But, studies have shown that 28% of individuals who report insomnia also self-medicate using alcohol (7).
This is viewed as a safe choice that may seem helpful if you are not on any sleep aides. However, physicians found that insomniacs who were reliant on drinking to sleep also meet the medical criteria for alcoholism.
That’s because using alcohol to treat your insomnia cause dependency. And, it also degrades REM sleep especially when consumed in excess. Increased sleep disruptions as the night progresses will far worsen your insomnia and the exhaustion you feel the next day. So, it is better for you to wait to fall asleep if you aren’t currently on a sleep aide (7).
You may experience sleep apnea
As we previously discussed alcohol has a notable effect on slow-wave-sleep especially during the first half of your slumber, however, this artificial increase of deep sleep increases vulnerability to sleep apnea (1). Not only does the likelihood of sleep apnea increase for individuals who are prone to this sleep disorder but sleepwalking without recollection of doing so also increases when you drink alcohol prior to bed (1). If you aren’t prone to sleep walking and sleep apnea the likelihood of these occurrences after a few drinks does decrease slightly, but if you are prone to these conditions, alcohol will make episodes more common (1).
You’ll visit the bathroom during the night
Alcohol is a well-known diuretic. It causes your body to excrete up to ten milliliters of fluid for every gram of alcohol you consume (5).
This fluid increase that becomes urinary waste occurs because alcohol reduces your body’s production of vasopressin, which is a hormone that’s typically responsible for telling you kidneys to reabsorb fluid.
The decrease of vasopressin causes more fluid to move to your bladder. As a result, more frequent urination occurs. This is why you’ll experience more sleep disruptions to get up and go to the bathroom.
This typically happens during the latter half of the night. Drinking more you will wake up more often to go to the bathroom. Thus, more alcohol increases sleep disruptions.
And, if you struggle to fall back to sleep after waking up during the night, these frequent bathroom breaks can outweigh the increase in deep sleep you get from having a drink before bed.
It increases your risk of sleep walking and eating
As we discussed above, alcohol use can cause an increase in several sleep disorders. These include sleep walking and a few others. But, what we didn’t mention is that you will be more likely to sleep eat as well (1).
Alcohol increases slow-wave-sleep also known as deep sleep. And, this sleep stage is when sleep walking occurs. It is the reason why sleep activities increase with alcohol consumption (3).
So, if you are prone to sleepwalking, sleep talking, or sleep eating, alcohol will increase the prevalence of these episodes.
It’s also worth noting that it your typically remember the times you sleepwalk, or sleep eat, alcohol especially when consumed in excess will make it almost impossible to recall these instances because of the extended slow-wave sleep.
How does alcohol effect sleep in men and women
Men and women have a less restful slumber during nights where they consumed alcohol before bed. However, this restlessness is more disruptive for women who drank before bed than it is for men (11).
Research shows that women who were equally intoxicated as their male counterparts had more sleep disruptions and more trouble falling back to sleep when they awoke during the night.
That said, more research is necessary to figure out why this happens. But, current evidence shows this trend occurs because women metabolize alcohol faster than men.
So, once your body metabolizes the alcohol you consumed, you may wake up. This is partially due to the stimulating effect the chemicals released into your brain after alcohol is processed have.
Is Alcohol Before Bed Always Bad?
While it may sound attractive to have a glass of wine, drift off to sleep, and enjoy more time in a deep, restorative sleep at night, the benefits of drinking before bed do not outweigh the detriments (1).
As we discussed earlier, you will spend more time in the stage three and stage four, restorative phases of sleep after having a couple of drinks.
But, you will also experience sleep disruptions during the REM phase of sleep. Allowing this to happen can damage your memory and learning capacity (1).
Just as importantly, you lose more sleep at night than you gain when you drink before bed. even if it does help you fall asleep sooner.
That said, we aren’t trying to say alcohol before bed is always bad thing. But, drinking too much before calling it a night will do you more harm than good.
How Much Alcohol Before Sleep? What’s Okay and What’s Too Much
We just discussed that drinking a little won’t mess up your sleep too bad. But, drinking too much will cause so much disruption that you’ll feel like you’ve hardly slept at all.
So, how much is too much? Unfortunately, the answer is complicated.
That’s because there isn’t one generalizable answer. The reason for this is that every individual metabolizes alcohol differently.
Any alcohol right before bed will cause some sleep disruption. That’s because it hasn’t been completely processed by your body before you fall asleep (1).
That said, individuals who have one drink right before bed, however, will have less sleep interruptions than individuals who have four or five drinks before bed (5).
The ideal amount to drink before bed is either not drinking at all, or whatever amount of alcohol your system can process completely. The latter works because your body is capable of removing alcohol from your system completely before you lay down (11).
As such, knowing your basal metabolic rate can give you a good idea of how quickly your body’s metabolism can break down alcohol. To do so, you’ll need to do some blood tests to help you determine this value because it varies from person to person.
How Long Before Bed Should You Stop Drinking Alcohol?
For every ounce of alcohol you consume, it takes your body about an hour to completely metabolize it.
So, if you have one shot, you should stop drinking an hour before bed.
But, if you have two shots, you should stop drinking two hours before bed.
The more your drink, the longer it takes for alcohol to get out of your system (12).
That said, when you are legally intoxicated with a blood alcohol level of .08 or above, it will typically take just under six hours for your body to process it (12).
However, if your body has time to completely metabolize the alcohol before you go to bed, drinking should not negatively impact your sleep.
So, that after-work happy hour drink shouldn’t impact your sleep if you give your body enough time to break down the alcohol you consumed.