Human Body

Why Alcohol Makes You Drunk, Molecule by Molecule

Quick answer

Why Alcohol Makes You Drunk, Molecule by Molecule

Alcohol makes you drunk primarily because of ethanol, a compound produced when yeast ferments sugars in plants. Once in the bloodstream, ethanol affects different organs: the liver oxidises it slowly, an empty stomach absorbs it faster, the brain releases feel-good hormones before cognition is impaired, and the lungs expel around five percent, producing the smell on a drunk person's breath.

Why alcohol makes you drunk??
Why alcohol makes you drunk??

You've probably met someone so drunk they could barely stand straight, with breath strong enough to stun a mosquito and, somehow, the confidence to move a mountain. It raises a fair question: what is it about alcohol that makes it such a powerful potion?

Before we get into the science, it's worth noting that the word "intoxicated" literally means "poisoned inside." That's more accurate than most people realise.

Meet ethanol, the culprit

The main character behind the effect is a compound called ethanol. It's the chemical that quite literally grabs hold of your senses. Ethanol is produced largely by the processing of yeast fermenting the sugars found in plants. Brew it from barley and you get beer; from grapes, wine; from potatoes, vodka. Each drink carries a different concentration, but the molecule doing the work is always the same one.

It's a matter of how fast it reaches your blood

How alcohol affects you depends on a range of characteristics, including age, gender, body metabolism, the percentage of alcohol in what you're drinking, and whether you've drunk it on an empty stomach or a full one. But the single most important factor is how quickly the alcohol enters your bloodstream, because that's all it needs to begin its work.

Alcohol also behaves differently in different organs of the body.

The liver

Your liver is the organ working to keep you as sane as possible. It tries to oxidise the alcohol, converting it into water and carbon dioxide. The catch is that it can only handle a very small amount in any given hour. So if you keep gulping down cans, or even buckets, of alcohol, the liver simply can't keep up, and you end up stumbling around unable to stay on course. Putting too much strain on the liver, through heavy drinking, can also lead to cirrhosis.

The stomach

Once alcohol reaches your gut and intestines, how long it stays depends on whether there's food in your stomach. If it's empty, your blood alcohol level can spike, making you feel intoxicated much more quickly. This is why drinking on an empty stomach hits so much harder — there's no food to slow the absorption down.

The brain

When alcohol travels through the bloodstream to the brain, it triggers the release of the feel-good hormones dopamine and serotonin, which is why it can leave you happy and carefree at first. Then it gradually starts to affect cognition, bringing on slurred speech, blurred vision and a loss of coordination.

The kidneys

In the kidneys, alcohol triggers ADH, or anti-diuretic hormone, which in effect commands the kidneys to release water and send you running to the toilet. That's the reason a drink or two always seems to bring on a trip to the restroom.

The lungs

Believe it or not, your lungs also remove alcohol, taking out around five percent. That's why you notice that distinctive smell on a drunk person's breath, and it's the same principle that lets breathalysers detect alcohol.

The speed at which all of this happens varies from person to person. Age, gender, body weight, genetics and even how well-rested you are all play a role in how quickly you feel the effects.

A gentle warning

Alcohol can have a serious impact on our lives when consumed excessively, and in the worst cases it can even turn fatal. So choose your potion wisely. Moderation matters more than the label on the bottle, and knowing what's happening inside your body is the first step toward making smarter choices about it.

Now you know a little more about what makes you drunk. You don't need alcohol to feel curious, though — the mind does that all on its own.