If you drink alcohol, chances are you’ve had a night where a few drinks left you feeling drowsy. Alcohol is a depressant, which means it can help you fall asleep faster (and in fact, the National Sleep Foundation estimates that 20 percent of Americans use alcohol to help them fall asleep — which is not recommended). However, it can affect the quality of your sleep, and not in a good way.
In 2013, researchers reviewed 20 studies looking at alcohol and sleep. “This review confirms that the immediate and short-term impact of alcohol is to reduce the time it takes to fall asleep,” Irshaad Ebrahim, director of the London Sleep Center and lead author of the review, said in a statement. “In addition, the higher the dose, the greater the impact on increasing deep sleep.”
Here’s how drinking affects your sleep quality at night.
Alcohol can interrupt your circadian rhythm and cause you to wake up in the middle of the night.
A 2010 study found that chronic drinking disrupted circadian rhythms. “This altered expression is closely related to circadian rhythm dysfunction and might link to a variety of physiological problems such as sleep/wake cycle dysregulation, depression, and even cancer,” study author Sy-Jye Leu, a researcher at Taipei Medical University, said in a statement.
Too much booze can interfere with REM sleep.
A 2013 review of studies found that alcohol reduces REM sleep, though the level of interference depends on how much alcohol you’ve consumed. FYI, REM sleep is associated with learning and memory consolidation, and it’s considered incredibly important.
Alcohol is a diuretic, so you may wake up more often to go to the bathroom.
Alcohol actually decreases how much anti-diuretic hormone your body produces, causing lowered reabsorption of water. So, your kidneys kick into gear and your body loses more fluid through urination. After a night of drinking, you may wake up needing to go, even if your bladder doesn’t typically bother you at night.
If you have breathing problems, alcohol can make them worse.
Alcohol decreases your muscle tone, including the tissue in your airways. This can make things like sleep apnea and snoring significantly worse.
Drinking can cause disruptive dual-activity brain patterns.
A 2015 study found that people who had a drink before bed experienced more slow-wave sleep patterns and something called delta activity, which is related to restoration and healing. But people in the study also had heightened alpha wave patterns at the same time as the delta wave patterns. Alpha waves are usually observed when someone is awake, but resting. The two waves together can offset each other, causing less restful sleep. TIME reports: “In previous studies, such warring alpha-delta brain patterns during sleep have been linked to daytime drowsiness, waking up not feeling rested, and symptoms such as headaches and irritability.”
[Editor’s Note: The information provided should not be considered a substitute for professional medical advice. Please consult a medical expert if you have questions related to your own health.]
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Joe Auer is the editor of Mattress Clarity. He mainly focuses on mattress reviews and oversees the content across the site.
He likes things simple and take a straightforward, objective approach to his reviews. Joe has personally tested nearly 250 mattresses and always recommends people do their research before buying a new bed. He has been testing mattresses for over 5 years now, so he knows a thing or two when it comes to mattress selection. He has been cited as an authority in the industry by a number of large publications.
Joe has an undergraduate degree from Wake Forest University and an MBA from Columbia University.