Many of us think that having a few glasses of wine at night will help us to sleep, which is where the common phrase ‘night cap’ originated.

However, research shows that this is not the case. Whilst alcohol can help initially in getting off to sleep, it causes us to wake up throughout the night, disrupting sleep and causing us to wake feeling tired.

Here is what happens after drinking alcohol at night:

  • Alcohol disrupts the bodies daily biological/circadian rhythms which modulate our physiological functions and behaviours, such as, body temperature, hormone secretions and the sleep/wake cycle.
  • Alcohol increases the fast onset of sleep, due to the production of a sleep-inducing chemical (adenosine). However, this quickly subsides causing us to wake and toss and turn throughout the rest of the night and wake fully before we are rested. In addition, REM sleep (Rapid Eye Movement – where you dream) is negatively affected so you will feel tired for the day no matter how long you try and stay in bed. This is the stage of sleep that helps boost memory, concentration, and learning.
  • Alcohol is a diuretic so it will increase your need to go to the toilet in the night. It causes us to sweat more leaving us dehydrated and waking up needing a drink of water. This is also why many people have headaches after drinking.
  • Alcohol can also cause snoring as it relaxes the muscles in the body making the throat, mouth and nose muscles vibrate.
  • Women’s sleep is effected more than men – even if they consume the same amount of alcohol. This could be due to women metabolising alcohol at a quicker rate, causing the sedative properties to wear off sooner, meaning women reach the less restorative stage of sleep before men.
  • Alcohol consumption can trigger new sleep disorders or exacerbate existing ones, including insomnia, sleep walking and sleep eating and obstructive sleep apnoea.

Alcohol is a powerful chemical that can have a wide range of adverse effects on almost every bodily system, including the brain, bones and heart. Drinking too much, on a single occasion or over time, can take a serious toll on our health not just our sleep. Here are other health problems associated with alcohol intake:

  • Brain – Alcohol interferes with the communication pathways in the brain, effecting mood, clarity, coordination and behaviour. It can cause blurred vision, slurred speech, slowed reaction times, impaired memory and depression. Excessive alcohol intake can cause black-outs and memory lapses, which can be very dangerous.
  • Heart – Drinking a lot over a long period of time or too much on a single occasion can cause heart problems such as high blood pressure, strokes and irregular heart beat (arrhythmias).
  • Bones – Alcohol negatively impacts the bones as it interferes with the balance of calcium, reducing calcium stores in the body.
  • Liver – Heavy drinking puts a lot of strain on the liver, which can lead to fatty liver disease, fibrosis, cirrhosis and alcoholic hepatitis.
  • Immune system – Too much alcohol can weaken the immune system, making your body a much easier target for illness and disease. Binge drinking slows your ability to fight off infections, even up to 24 hours after being ‘drunk’.
  • Cancer – See the National Cancer Institute Alcohol Fact Sheet

If you would like to keep a track of what you are drinking, download the Drinkaware app.

Click here for tips on cutting down on alcohol.



Arnedt JT. (2011). A 2011 study into the effect of intoxication on healthy young adults Sleep following alcohol intoxication in healthy, young adults: effects of sex and family history of alcoholism.

Drink Aware (2019) –

 Natural Sleep Foundation (2018) –

NIH (2019). Alcohol’s Effects on the Body –

NHS (2019)

Roehrs, T. and Roth, T. (2001). Sleep, sleepiness, and alcohol use. Alcohol research and Health, 25(2), pp.101-109.

Posted by Sarah@Kaido

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