Alcohol can have a sedative effect and cause a person to fall asleep more quickly than usual. However, consuming alcohol can also cause sleep disruption and other adverse effects on people’s health.

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In this article, we explore the sedative effects of alcohol and ways to avoid this from occurring. We also discuss the possible negative effects of alcohol on the body and sleep.

Alcohol depresses the central nervous system and has a sedating effect.

The substance causes sleepiness by increasing the functioning of the gamma-aminobutyric acid (GABA) neurotransmitter. The GABA’s main function is to slow down body and brain activity.

As alcohol enhances the GABA’s function, it causes a slowing of brain activity, which can make a person feel sleepy and tired.

An older study concluded that alcohol might reduce sleep in the first half of sleep and increase disruption in the second half.

While alcohol consumption may help someone fall asleep, there is a reduction in sleep quality compared with sleep without alcohol. The former may also include substantial periods of wakefulness.

Learn more about sleep stages.

If a person plans to consume alcohol but wants to avoid disrupted sleep, they can take measures to help plan an adequate sleep. These include:

  • Allowing time between drinking and bedtime to metabolize alcohol: A person may want to cut off drinking a few hours before bed to prevent sleepiness or restlessness from alcohol.
  • Reducing waking to urinate: A person can do this by going to the bathroom before bed.
  • Avoiding drinks containing caffeine: These beverages can cause further disruptions to sleep.
  • Maintaining a regular sleep schedule: This may help a person avoid sleepiness and sleep disruption.
  • Being physically active regularly during the day: This may also help improve sleep hygiene.

Read more about improving sleep hygiene.

Although alcohol can initially have a sedative effect, it can lead to problems in the sleep cycle. These negative effects include the below.

Less REM sleep

Drinking alcohol can disrupt the rapid eye movement (REM) phase of sleep, an important, restorative stage of deep sleep during which dreaming occurs.

However, researchers do not agree on how alcohol interferes with REM sleep. Research from 2020 states that alcohol reduces sleep quality, and while it may not significantly reduce REM sleep, there is dysregulation. Alcohol may also result in suppressed REM sleep in the short term.

Older research suggests the effects on REM sleep appear to be dose related. Low and moderate doses of alcohol tend not to affect REM in the first half of sleep, while high doses of alcohol significantly reduce REM sleep reduction in the first part of sleep.

Research from 2018 corroborates this, suggesting that people experience a lower duration and quality of REM after consuming alcohol.

Disrupted sleep cycle

Alcohol can lead to fragmented sleep and waking up during the night, as it disrupts the sleep cycle.

Research from 2018 has found that alcohol can disrupt the sleep cycle and cause fragmented sleep. As a result, people may:

  • enter lighter stages of sleep from deeper ones
  • wake up frequently
  • remain awake for longer periods between sleep after alcohol consumption

Night awakenings and insomnia

People’s tolerance to alcohol as a sleep aid rapidly increases, leading to insomnia and alcohol dependence.

Regular use of alcohol as a sleep aid can be counterproductive. Although it may initially help a person fall asleep, the long-term effects tend to involve less quality sleep and may even lead to the development of sleep disorders such as insomnia. Insomnia refers to a difficulty in:

  • falling asleep
  • remaining asleep
  • getting quality sleep

Researchers believe the link between insomnia and alcohol consumption to be bidirectional, meaning that each contributes to the other.

Insomnia due to alcohol consumption can increase the risks of various health issues, which include:

Worsen sleep apnea

Alcohol can worsen sleep apnea, a condition where a person’s breathing stops and regularly starts while they sleep. This can prevent enough oxygen from reaching the body.

Worsen snoring

Alcohol consumption can lead to worsened snoring and induce sleep apnea, which prevents oxygen from reaching the body during sleep.

Sleep talking and walking

Alcohol consumption can be a trigger for sleepwalking or talking during sleep. Sleepwalking can lead to injuries, disrupt sleep, and leave a person feeling fatigued and not well-rested after waking.

Learn more about sleep from our dedicated hub.

Disrupted sleep can also cause various negative effects on a person’s general health. These include:

Raising stress hormones

Alcohol causes a higher production of the stress hormone cortisol, which regulates the body’s stress response and initiates wakefulness. Disruptions to this hormone can lead to reduced quality sleep and cognitive difficulties.

Heart rate increase

Alcohol consumption may raise a person’s heart rate, and it also has links to various cardiovascular conditions, including:

During sleep, a person’s heart rate should slow and drop to below 60 beats per minute. A racing heart may disrupt sleep or cause someone to fully awaken.

Affects learning and memory

Alcohol consumption can lead to a lack of sufficient quality sleep, which can seriously affect cognitive functions such as learning and memory.

Research has found that people’s ability to remember, pay attention, and carry out cognitive functions declines with a lack of sleep.

Hot flashes

Some individuals find that alcohol consumption can trigger hot flashes and night sweats during menopause. However, more research is necessary to determine whether this is a common occurrence.


Alcohol is a diuretic, meaning it causes a person to need to urinate more frequently. This may cause them to disrupt their sleep to empty their bladder.

Alcohol can cause sleepiness and may initially have a sedative effect. This is because it depresses the central nervous system and enhances the effects of the GABA neurotransmitter, which slows brain activity.

However, a person’s sleep quality after alcohol consumption is generally worse. People who consume alcohol may wake up during sleep and experience increased disruptions such as sleep apnea and snoring.

Alcohol disrupts the sleep cycle and generally leads to lower quality sleep. Experts also associate it with insomnia, which can increase the risk of other health conditions, such as diabetes, cardiovascular disease, and cognitive difficulties.