What Are the Effects of Alcohol on the Sleep?

Sleep is as essential as oxygen and a consistent lack of it can lead to everyday fatigue and bad mood.

Regular sleep deprivation can also lead to more serious health complications; including diabetes, obesity, and heart disease, a decrease in life expectancy, and an increased risk of depression and anxiety.

Despite the necessity of sleep, why do one in three people suffer from poor sleep? [1]

Sleep disturbances via alcohol are one of the most concerning reasons.

Excessive alcohol consumption exceeding the recommended weekly alcohol intake can often result in reduced sleep quality, insomnia, and sleep Apnoea; due to the negative effect alcohol has on the nervous system. [2]

Does Alcohol Help You Sleep?

It’s a common misconception that alcohol can be used sleep aid. The sedative effect of alcohol means it slows down the brain and lulls the body into a false sense of sleepiness; fooling sleepers into believing a few drinks will help them sleep.

This is both incorrect and dangerous as it can lead to alcohol dependency; as those with alcohol use disorders often choose bedtime to consume alcohol to improve their sleep or cure insomnia.

Several studies have found that consuming alcohol just before bedtime may appear beneficial as it increases drowsiness in the short term; however, it later causes frequent and earlier awakenings.

This is a detrimental disruption to sleep patterns and deep sleep. Daytime fatigue, cognitive issues, and increased consumption due to an increased tolerance are just some of the consequences. [3]

Importance of Sleep & Sleep Cycles

To understand how alcohol can affect sleep it’s important to understand the different stages of the sleep phase. An eight-hour cycle consists of four separate stages: three non-rapid eye movement (NREM) stages and one rapid eye movement (REM) stage.

  • Stage 1 of NREM: Otherwise known as light sleep, lets the body shut down into sleep as the body passes from wakefulness into sleep. Breathing, eye movements and heartbeat start to slow, the muscles relax, and brain activity begins to decrease
  • Stage 2 of NREM: This longest of the four sleep cycles allows several changes to occur and allows the body to slip into a deeper slumber. The heartbeat, breathing rate and body temperature all decrease as the eyes become still
  • Stage 3 of NREM: All bodily facilities reach their lowest levels, including the heartbeat, breathing rate, and brain activity. The muscles become completely relaxed as eye movements cease. This stage is known as slow-wave sleep
  • Stage 4 (REM sleep): In the last stage the most dreaming takes place and potential memory consolidation is reached. Eye movements will restart and breathing rates and heartbeat will quicken. ([4]) A full night’s sleep of eight hours should see the sleeper go through four to five cycles of these stages: repeating together in a recurring cycle lasting approximately 90 to 120 minutes [5]

The brain and body use sleep to recover from the exhaustion of the day’s activities. The introduction of alcohol can have implications due to the effect on the central nervous system and increase in excessive thirst and sweating from dehydration.

This results in a disruption in these essential sleep cycles and an inability to experience sufficient REM sleep.

Therefore, the harmful physical effects of alcohol can lead to the reduction of time spent in recuperative sleep; with consequences such as tiredness, cognitive and memory impairment, and mood disturbances.

An increased compulsion to drink daily before bedtime can also ensue as the sleeper’s alcohol tolerance builds, resulting in further reliance on alcohol.

Sleepers may think they need to keep drinking to get to sleep but are usually unaware that their ensuing fatigue and low-quality sleep are likely to be caused by the effects of alcohol consumption prior to bedtime. [6]

Alcohol and Your Health

The interruption of sleep cycles via alcohol-related frequent wakings has further health implications. Researchers have found a correlation between alcohol intake and increased risk of insomnia, which can have increased mortality implications.

Chronic insomnia can be referred to as the difficulty falling to sleep or staying asleep for a period of three weeks or more. [7]

Do you have difficulty falling asleep or find yourself waking frequently in the night? Are you finding yourself waking too early or feeling drowsy in the day? If you suffer from these symptoms you may suffer from Insomnia. If so, please seek medical assistance rather than self-medicate with alcohol. Alcohol exacerbates insomnia and should not be used sleep aid. [8]

Sleep Apnoea Obstructive is another unpleasant effect of alcohol-related sleep problems. The apnoea suffer will find themselves suffering frequent pauses in their breathing during sleeping, lasting around 10 to 30 seconds. Alcohol can cause this as it relaxes the throat muscles and can block or reduce the brain’s ability to wake when there is a lack of oxygen.

The body would normally detect this when not inebriated. For those already suffering from Sleep Apnoea, it is recommended that they avoid drinking alcohol completely or reduce the amount/frequency of consumption.

Differences between Heavy and Moderate Drinking

Although it is widely believed that it’s safe to drink in moderation, researchers have found a secure link between alcohol consumption and increased non-REM sleep, and subsequently a lack of deep sleep. Studies have shown consistency in the amount of REM sleep a sleeper experiences in the first part of the night if the sleeper has drunk lightly or moderately.

However, those who drink heavily were found to experience a greater reduction in REM sleep during their initial stage of sleeping. When observing the whole night, the researchers noted that non-REM sleep had a direct connection to the amount of alcohol consumed before bedtime.

Although the studies were not able to shed light on the effect of alcohol on light alcohol consumption, consuming a moderate to the high amount of alcohol demonstrated a trend towards increased non-REM sleep, depending on the amount consumed.

Therefore, the researchers felt secure enough in their findings to conclude a direct link between the reduction in REM sleep and increased alcohol consumption. [9]

Due to the individual nature of the human body, what might be considered light drinking for one may affect another person differently. Regardless of this, further research in a 2018 study found that drinking excessively will probably have a more negative effect on sleep quality than light or moderate drinking.

Even small amounts of alcohol can have a negative effect on sleep quality, even as the effects differ between individuals. [10]

Setting Up Healthy Sleep Strategies

It’s always best to try to set up and maintain good sleep habits, to make sure you get the restorative sleep that the body needs.

Here are some helpful methods for improving sleep quality:

  • Try to abstain from alcohol at least four hours after bedtime [11]
  • Develop consistent bedtime and wake time
  • Avoid stimulants such as caffeine several hours before bedtime
  • Use a sleep meditation video or recording
  • Listen to relaxing nature sounds or a sleep story
  • Regular physical exercise can be helpful (but not too near to bedtime)
  • Try not to nap
  • Find ways to relax before bedtime; read a good book, take a warm bath etc
  • Avoid the use of portable electronic devices near to bedtime (e.g., phones, tablets, laptops)


  1. https://www.nhs.uk/live-well/sleep-and-tiredness/why-lack-of-sleep-is-bad-for-your-health/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4666864/ 
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4666864/#B19
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3768102/
  5. https://www.ninds.nih.gov/Disorders/patient-caregiver-education/understanding-sleep
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4666864/#B19
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775419/
  8. https://www.albertahealthservices.ca/assets/info/amh/if-amh-alcohol-and-sleep.pdf
  9. https://www.albertahealthservices.ca/assets/info/amh/if-amh-alcohol-and-sleep.pdf
  10. https://pubmed.ncbi.nlm.nih.gov/29549064/
  11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775419/