What happens to your body when you drink alcohol?

For many people, alcohol is part of the festival atmosphere, but the body rarely gets much of a break during a festival. Every drink has to be broken down before the body can deal with anything else, and the liver works at its own pace. Coffee, sleep, dancing or fresh air may make you feel more awake, but they do not remove alcohol from the body any faster.

At a festival, the effects of alcohol are often more noticeable than at a typical party because people tend to drink over several days, sleep less, eat differently and are socially active for many hours. Research shows that alcohol can affect sleep, energy levels, mood, concentration, reaction time and judgement. It can also make it harder to recognise your own limits and know when to stop.

That is why it is a good idea to think of a festival as a marathon rather than a sprint. Small choices along the way, such as drinking more slowly, eating before drinking and taking alcohol-free breaks, can make a big difference to how you feel on days two, three and four.

1. How quickly does the body break down alcohol?

Alcohol takes time to break down. As a rule of thumb, the body breaks down around one unit of alcohol per hour, although this varies from person to person. If you have been drinking late into the evening or during the night, there may still be alcohol in your system the following morning.

This means that you may not necessarily be ready for the next day of the festival, to cycle, or to make good decisions simply because you have slept for a few hours.

2. What happens when you drink alcohol several days in a row?

Drinking alcohol over several consecutive days puts a strain on the body. When you drink heavily for several days, the body has less time to recover. Alcohol can affect sleep, recovery, blood sugar levels, the stomach, concentration and mood.

Research suggests that repeated days of drinking can interfere with the body's ability to recover, partly because alcohol affects sleep quality and the liver's metabolism. As a result, the effects of alcohol can build up over the course of a festival, leaving you feeling more tired, irritable or low on energy, even if you are not drinking more than the day before.

3. How does alcohol affect sleep?

Alcohol can lead to poorer sleep.

Alcohol has a sedative effect and may make it easier to fall asleep, but that does not mean you will get a good night's sleep. Alcohol disrupts the normal sleep cycle and can particularly affect REM sleep, which is important for memory, learning and emotional balance.

As the body breaks down alcohol during the night and blood alcohol levels fall, sleep often becomes lighter and more fragmented. As a result, many people wake up earlier or sleep more restlessly after drinking alcohol. As a result, you may sleep for many hours but still wake up feeling tired, irritable and poorly rested.

At a festival, the effect can be even more pronounced because alcohol is often combined with late nights, noise, light, heat, constant sensory stimulation and several days of too little sleep.

4. Why does alcohol affect judgement?

Alcohol makes it harder to recognise your own limits because it affects judgement and impulse control. As a result, it can become more difficult to judge when you have had enough or to resist pressure to drink.

It can also make it harder to notice when a friend needs help or when you yourself are heading into a situation you would otherwise have avoided.

5. Can you drink alcohol more safely?

It is possible to drink more safely. It is not only about avoiding alcohol altogether but also about making it easier to know when to stop and take care of your body along the way.

Small decisions before and during the festival, such as taking alcohol-free breaks, drinking more slowly and setting a limit in advance, can make a big difference to the rest of the festival experience.

The Danish Health Authority recommends that adults aged 18 and over drink no more than 10 units of alcohol per week and no more than 4 units on the same day.

Drinking less alcohol can make a significant difference without taking away from the festival experience. Research indicates that there is no risk-free lower limit for alcohol consumption, so the less you drink, the better you protect your body. As a liver researcher, my best advice is simple: drink less, and consider avoiding alcohol altogether.