Why do we often have trouble sleeping after drinking alcohol?

New Year’s Eve parties are often a time of merrymaking and plenty of alcohol. For some people, it can be difficult to stay sober after drinking and this can quickly lead to them taking a nap on the sofa or falling asleep.

However, when you wake up, the feeling of fatigue is even greater, you do not feel like you have rested at all. So why does this feeling still exist?

The effects of alcohol on sleep

There is a misconception that drinking alcohol helps you relax due to its sedative effects. Dr Sophie Bostock, sleep expert and founder of the websiteTheSleepScientist, explains that alcohol increases what is known as sleep pressure, one of the main sleep control systems, and is related to the buildup of a chemical called adenosine, which makes you sleepy. However, alcohol can also delay bedtime due to its effect on circadian rhythms. Alcohol reduces melatonin production and can slow down the body clock. Alcohol also negatively affects the quality of sleep. When alcohol is metabolized by the liver, it acts as a stimulant, making it easier to wake up, so you spend less time in deep sleep. When this sleep stage is disrupted, you wake up more easily and may feel a little groggy. So even if you have slept for a significant number of hours, you still don't get restorative sleep.

A fact that makes people who are already tired and sleep deprived even more exhausted after drinking alcohol and falling asleep.

How much alcohol affects sleep?

Not everyone is affected by alcohol in the same way. This depends on metabolism, weight or genetics, although excessive alcohol consumption can exacerbate the disruptive effects of sleep. Dr Bostcok explains that we metabolise alcohol at different rates at different times, but the body is most efficient during “happy hour”, around 5pm. This is when body temperature naturally rises. The most important thing is to make sure you don’t drink every night of the week to get the most restorative sleep, and to follow official recommendations, it’s best not to drink alcohol every day.

Finally, it is clear that people who are stressed often have more difficulty sleeping after drinking alcohol. So drink alcohol in moderation and avoid drinking late into the night.

For a good night's sleep

• Going to bed and waking up at a fixed time helps stabilize your body's biological clock and improve sleep quality.
• Be active during the day.
• Limit caffeine such as tea and coffee in the evening, and avoid drinking alcohol a few hours before bedtime.
• Eat dinner early, at least 2 - 3 hours before bedtime.
• Limit exposure to blue light in the evening.