Alcohol makes most people feel drowsy minutes to hours after drinking, so when people have difficulties falling asleep at night, many turn to alcohol. However, alcohol can actually make your sleep worse.
When you drink alcohol, the total amount of sleep you get throughout the night is likely to be reduced. Sure, it makes you feel drowsy, but as it starts to wear off while you are asleep, you start to have many more awakenings and restlessness in the second half of the night, reducing your total sleep time.
Alcohol also affects your stages of sleep. It suppresses REM sleep, but as the alcohol wears off the second half of the night, you then have a rebound (or increase in REM sleep). With an increase in REM sleep, you are likely to have many more awakenings. The fragmentation and reduction of your sleep makes you feel less rested the following day and leads to clouded thinking.
Many people with insomnia self-medicate in an attempt to facilitate sleep, and alcohol is often turned to. In addition to this decision not helping sleep as noted above, it can lead to obviously bigger concerns of contributing to an alcohol use disorder. Despite much evidence demonstrating that alcohol leads to overall poorer sleep, some people think that alcohol helps them sleep. However, the perceived initial “benefits” often wear off after a few days to weeks, which often results in people drinking more and more to achieve the “benefits.”
Chronic alcohol use can lead to long-term problems with sleep. In people achieving abstinence in the setting of prior alcoholism, the effects of alcohol on sleep can persist many years despite no alcohol use. If you think you or someone else you know may have problems with alcohol use, please seek help. The following sites may provide a starting point for help: National Institute on Alcohol Abuse and Alcoholism or DrMelissaWelby.com.
Alcohol can also worsen other sleep disorders. Alcohol is a respiratory depressant, which means that it can slow your breathing and make it less effective. Due to these effects, it can worsen obstructive sleep apnea if you already have it or can cause you to have sleep apnea if you don’t have it in the absence of alcohol. It may also lead to your oxygen being low and your carbon dioxide levels being elevated during sleep. Alcohol may also worsen restless legs syndrome or leg kicks (called periodic limb movements) throughout the night.
So how soon before bedtime should you cut off alcohol intake to not have these effects? Even afternoon light drinking has been shown to disrupt sleep. A study where subjects drank in the afternoon but their blood alcohol level was 0.00% at bedtime still demonstrated increased awakenings throughout the night, reduced total sleep time, reduced REM sleep, and reported more “superficial” sleep.
So if you are having difficulties sleeping, don’t turn to alcohol in an attempt to facilitate sleep, and remember that it can actually worsen sleep and cause or worsen other sleep disorders.
Also, remember to never drive or engage in activities requiring a high level of attention when drowsy.