What Happens When You Drink Alcohol Before Bed
Alcohol can affect individuals differently and even affect the same person in different ways at various times, depending on factors such as how much and how quickly alcohol is consumed. But in general, when you drink alcohol close to bedtime, you will fall into a deep sleep more quickly, explains Ronald Chervin, MD, a professor of neurology and director of the Sleep Disorders Centers at the University of Michigan in Ann Arbor.
However, as the enzymes in your liver metabolize the alcohol, removing it from your body, the sedating effect wears off. That leads to a “rebound effect” in which you experience lighter, more disrupted sleep. “People tend to sleep better the first half of the night and then have more sleep fragmentation during the second half of the night,” says Dr. Benjamin.
Research shows that alcohol essentially disrupts the normal deep sleep and rapid eye movement (REM) sleep cycles (the stage of sleep when most dreaming happens), which can lead to shorter sleep time and more fragmented and lighter sleep. “Alcohol tends to destroy sleep architecture [structural organization of normal sleep] and delay dream sleep and leads to more awakenings and arousals,” says Alon Avidan, MD, MPH, director of the UCLA Sleep Disorders Center in Los Angeles.
Even a little alcohol can impact how well you sleep. According to an observational study cited by the Sleep Foundation, even low to moderate amounts of alcohol — two drinks or less for men and one drink or less for women — decreased sleep quality by nearly 10 to 24 percent.
Other Sleep and Safety Issues Impacted by Alcohol
In addition to fragmented, less restful sleep, alcohol can also have an effect on other sleep issues such as insomnia, excessive daytime sleepiness, and sleep apnea.
Insomnia
According to the Sleep Foundation, people who have alcohol use disorders often experience symptoms of insomnia, which is the most common sleep disorder. At the same time, many people with insomnia routinely use alcohol to fall asleep. Research shows that as many as 20 to 30 percent of people with insomnia report using alcohol to get some shut-eye, notes Dr. Avidan.
“Many patients with alcohol dependence have severe insomnia,” says Benjamin. “This may be a bidirectional process — meaning alcohol use for years caused sleep fragmentation or people with insomnia started drinking to sleep.”
Dependence on alcohol is a very real concern for people who have insomnia and routinely use it to fall asleep. A study published in 2018 in the journal Sleep, found that people with insomnia who relied on alcohol as a sleep aid experienced successful sleep onset initially but quickly developed tolerance, which led to increased alcohol intake.
“If someone has a glass of alcohol one week, they may need two glasses the second week and so on, as they become tolerant to the effects and need more,” notes Avidan. “The body becomes almost dependent on it and it creates a long-term dependency to alcohol.”
Excessive Daytime Sleepiness
Since using alcohol routinely to fall asleep leads to disrupted sleep, people can experience chronic daytime sleepiness. That can then create an unhealthy cycle of using stimulants such as caffeine to stay awake, then self-medicating at night with alcohol to fall asleep again, according to the Sleep Foundation.
Sleep Apnea
Alcohol can aggravate breathing-related sleep problems such as snoring and sleep apnea, according to an article published in December 2019 in the journal Current Opinion in Psychology. The authors advised that people with such sleep disorders should avoid having alcohol, especially before bedtime.
According to the Sleep Foundation, alcohol can relax the muscles of the mouth and throat, increasing the likelihood of the airway being blocked. And because alcohol initially makes it more difficult for a person to wake up, they can experience longer obstructions in breathing before they’re roused enough to breathe normally.
Risk of Falls
Having alcohol before bed can also increase your risk of falls if you get up during the night, due to instability and unsteadiness, notes Avidan. This can be particularly dangerous for older adults, he adds.
Plus, alcohol is a diuretic, making it more likely that you’ll need to get up to urinate, according to the Sleep Foundation.
Tips for Sleeping Better if You Plan to Have a Drink or Two
So what can you do to mitigate the effects of alcohol on sleep if you know you'll be having a glass of wine with dinner or indulging with friends at your local watering hole? Here are some smart ways to lessen the impact of alcohol on sleep:
Don’t overdo it. The more alcohol you drink, the more your body will need to metabolize and the worse the impact on sleep. “Overall, alcohol should be consumed in moderation,” says Benjamin.
Don’t drink close to bedtime. According to Avidan, you should stop drinking at least four hours before you go to bed to reduce your risk of disrupted sleep. “It is best to drink early enough in the evening so that the alcohol is metabolized before going to sleep,” adds Benjamin.
Follow good sleep habits. Avidan suggests following a good routine for healthy sleep such as sticking to a regular sleep and waking schedule, avoiding blue light (such as from a TV or computer screen) before bed, not exercising too close to bedtime, and avoiding caffeine after noon.
Bottom line: Alcohol should not be used as a sedative to fall asleep, emphasizes Avidan. “If you’re regularly having trouble falling asleep, see your family physician,” he recommends. “And if the problem persists, see a sleep doctor.”
