What are alcohol's effects on the body?

It's mulled wine and champagne season. What happens in our bodies after consumption? More on the effects of alcohol, how it’s processed and its impact on driving – from tipsiness to alcohol poisoning.


A cup of mulled wine at the Christmas market, a little punch with the grandparents by the Christmas tree, champagne on New Year's – more alcohol than usual is flowing this time of year. But what actually happens in our bodies when we drink alcohol? Right after we start drinking, part of the alcohol gets into our blood via our mucous membranes. First via the mucous membranes of the mouth, oesophagus and stomach, then most of it via the intestines. Alcohol exerts a particularly rapid effect when it is heated, contains carbonation or sugar, or is drunk quickly or on an empty stomach. Eating before or during alcohol consumption ensures that the alcohol remains longer in the stomach, thus postponing its absorption by the intestines.

Consumption and processing of alcohol

Once alcohol is in the blood, its concentration in the body rises quickly, generally peaking after about an hour. Then the alcohol is slowly broken down by the liver.

The alcohol that is measured is detectable alcohol, i.e. that which the body has not yet processed. The more a person weighs, the faster he or she processes alcohol. This is because heavier people have more body water, in which alcohol is more quickly dissolved. But even if a man and woman are the same weight, the man will generally process alcohol faster, as women normally have more body fat and less body water per kilogramme. Women have an average of 55% body water versus 68% for men. This percentage is also used to calculate the per mille blood alcohol content. The formula is the following: Alcohol quantity in grams divided by 68% or 55% of body weight.

Adolescents process alcohol more slowly

Enzymes in the liver are responsible for processing alcohol. Adolescents have lower levels of these enzymes than adults. Moreover, women have fewer of these enzymes in their body than men. Various other factors, such as the intake of medications or individual or genetic conditions, can slow down the processing of alcohol.

Effects of alcohol

Alcohol exerts a wide range of effects on the body. This is apparent on an emotional level: alcohol is disinhibiting and makes us more jovial, louder and more aggressive. Meanwhile, it also influences various bodily functions, such as breathing. Caution should be exercised during activities that require a high degree of concentration, such as driving. Drink-driving can have fatal consequences. Our brain is affected when we drink, our field of vision is narrower, and our attention, responsiveness and powers of judgement are impaired – we react up to 50% more slowly. We also display a greater propensity to take risks.

From intoxication to alcohol poisoning

  • Up to 0.5 per mille alcohol, we feel a euphoric and disinhibiting effect.
  • Starting from 1 per mille, we are already in a state of intoxication and our behaviour is highly affected.
  • Starting from 2 per mille, we can barely respond anymore, being stupefied by the alcohol.
  • Starting from 3 per mille, the situation becomes truly dangerous: we may lose consciousness and fall into coma. Respiratory distress and respiratory paralysis can have fatal consequences. This is also referred to as alcohol poisoning.
  • Alcohol poisoning: The body loses a lot of heat and its temperature falls. Fatally, however, we may not notice this. On the contrary: the alcohol in our blood gives us the illusion of heat. The sensation of internal heat occurs because blood is directed to external body regions.

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