How Alcohol Affects Sleep

If you drink alcohol, be it wine, beer or a single malt regularly or even socially, you probably know that its consumption makes you sleepy at times. So don’t be surprised if we tell you that almost 20% of Americans use alcohol as a sleeping aid. But this habit, initially seemingly “harmless”, negatively impacts the sleep and can disrupt sleep cycles over a period and cause sleep disorders.

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    Even if you are a moderate drinker, drinking regularly does not really assist sleep, as is the popular misconception, but rather disrupts it. So what does it mean? Should you stop drinking alcohol completely? No, not really. But if you want to balance a sleep-friendly, healthy lifestyle, managing your alcohol consumption is important, so that it does not interfere with your circadian rhythm and disrupts your sleep.

    Alcohol-induced sleep also disrupts circadian rhythms, causes daytime fatigue and induces insomnia over a period. Now we don’t have the complete answers to why the body requires sleep, but we do know that lack of it is linked to depressive disorders, heart diseases and many other health issues. And a lack of night’s sleep will impair your occupational and social function, memory loss in some cases and sometimes even vehicular accidents.

    Why Is the Circadian Rhythm Important?

    The body’s processes are governed by circadian rhythms, such as sleep, sexual drive, metabolism, mood, cognitive functions and immunity. These timings also determine whether the body should feel groggy or wakeful, depending upon what time it is. Alcohol disrupts this cycle by interfering with this cycle’s ability to synchronize itself, and this itself can cause major changes. For example, your sleeping patterns might be affected as a result of consuming alcohol before going to bed. One thing is clear — alcohol and sleep don’t go together.

    Since the circadian cycle governs the major functioning of your body, this cycle being disrupted by alcohol use could have some widespread effects. These include:


    Depression is a common factor when it comes to people with alcohol problems. The alcohol is consumed in an attempt to cheer themselves; other times, it is consumed to help them sleep. People who have depression may already be suffering from disrupted circadian rhythm and the presence of alcohol in this equation could be disastrous. Overall, sleep, depression and alcohol do not mix very well.

    Bad Liver Function

    A functioning liver pulls toxins from the bloodstream, works as a filtering system for the body and helps metabolize chemicals and food. It also helps metabolize alcohol as a matter of fact. But like most of the body’s organs, the liver also works according to the circadian rhythms. We have already established that alcohol messes up the circadian rhythms; as a result, the rhythms regulating the lever are also compromised and hence, it may result in poor liver function, disease and liver toxicity.

    Interrupted Sleep-Wake Cycles

    Consumption of alcohol in the evenings suppresses melatonin, a sleep-inducing hormone. Melatonin is what regulates your sleep cycle and also a sleep enabler. Research has said that consumption of alcohol in the evenings reduces the production of melatonin by as much as 20%. Alcohol throws off the natural sleep cycle off-course and makes you feel sleepy at times when you should be wide awake.

    If you have gone to bed right after binging on alcohol, chances are that the first half of that sleep will be dreamless and uninterrupted. But there is the likelihood that the second half would be restless. In simpler terms, this is known as the rebound effect, where people who have consumed alcohol will find themselves wide awake in the early hours. And now you know that is not something to boast about.

    Sleep Rhythms at Loggerheads

    Consuming alcohol before bedtime causes the production of both alpha and delta waves. Delta waves are the lowest frequency of our brains, and these waves allow for the formation of learning and memory while you sleep, otherwise known as restorative sleep. They also help reduce the production of cortisol, a chemical which is secreted when a person is under stress. Alpha waves, on the other hand, occur when you are resting peacefully and are awake.

    When activated together because of the consumption of alcohol, the delta and alpha waves can disrupt the restorative sleep.

    A Decrease in REM Sleep

    Moderate to high intake of alcohol can reduce the percentage of REM (rapid eye movement) sleep throughout the night. The activity of the brain in this stage is similar to that of a wakeful state. Normally, during the REM sleep, the brain is very active, and adults spend about 20% of their sleep time in this stage. The first period of this REM sleep is disrupted by alcohol, resulting in less time to fall asleep and probably a deeper slumber, but the effects are very short lived.

    And a lack of REM can have a very damaging effect on your motor skills and concentration.

    Breathing Disorders

    Consumption of alcohol causes many side effects and one of them is relaxing your muscles. Yes, alcohol acts as a muscle relaxant, causing your muscles to relax, and your throat also happens to have muscles. If you are one of those people who suffer from sleep apnea, a common condition in the United States (millions are affected by it), which occurs when the upper passageway is blocked repeatedly during sleep, alcohol may increase the chances of it becoming worse. The air passage becomes so narrow that your natural breathing cycle is interrupted and this wakes you up. As a result of the lack of sleep, you feel tired the whole day the next day.

    Even if you do not suffer from it, alcohol has a tendency to induce symptoms like sleep apnea, that could include interrupted breathing or snoring in people who are otherwise perfectly healthy. The best way to avoid this would be avoiding consumption of alcohol several hours before your time to go to bed.

    You May Need to Pee, More Than Usual

    Like most people, you probably visit the bathroom once before you go to bed so that you won’t have to throw back the warm covers and rush to the loo once you are moving towards sleep comfortably. And even your body knows that because it has become habitual of this pattern. And surely, you may have noticed that if you consume alcohol in the evening, the need to urinate increases. And it is not just because alcohol is liquid. This irritating effect is caused because of an entirely different reason.

    Alcohol is a diuretic, which means that it makes the kidneys expel much more liquid than you have taken in. So, for every 1g or alcohol taken in, the excretion of urine increases by 10ml. At the same time, the consumption of alcohol also results in reducing the production of a hormone called the vasopressin, an antidiuretic hormone, which controls the amount of water absorbed by the kidneys.

    As a result, your kidneys reabsorb water instead of flushing it out through the bladder. Alcohol also increases the acidic content in your urine, and that irritates the lining of your bladder. This makes the bladder feel fuller than it is, which causes you to make multiple trips to the bathroom, and as a result, causing a sleepless night.

    Really Sweaty Nights

    Consuming alcohol will affect every part of your body including the circulatory system and the central nervous system. Its consumption causes vasodilation, in other words, the widening of blood vessels. And when the blood vessels that are closer to the skin, it causes the skin to become warm. As the skin warms up, it causes the sweat glands to produce the fluid called sweat in order to maintain the ideal body temperature.

    Although this is a normal reaction, it is also one of the common causes of sleep disruption. Common in people with alcohol dependency, night sweats can also occur after a session of binge drinking. And it is a common misconception that the body sweats this alcohol out; only 10% of the alcohol is expelled via breath, urine and perspiration. As a result of night sweats, your body loses a lot of moisture and can cause you a lot of discomfort (sometimes it can also cause hallucinations) and broken sleep.


    Those with a habit of having a few drinks before going to bed, the common problems include a longer time required to fall asleep (this changes if the person has consumed large quantities of alcohol), regular sleep disruptions, daytime fatigue and decrease in quality sleep.

    Also, a 2011 study showed that women react differently to alcohol, in the sense that it increased their deep sleep, but cut down on the REM sleep. Men experienced a decrease in both REM and deep sleep after consuming alcohol. So clearly, alcohol does not enhance your sleep, but seriously messes it up. While drinking small amounts may not do much harm, medium to large amounts can have many harmful effects on your sleep, and as a result, your health.

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