What happens when you drink

Published by Bupa’s Health Information Team, November 2010.

Most of us are familiar with the pleasant glow that follows a couple of drinks. But there are other effects that alcohol has on your body and mind which may surprise you.

This article explains what happens when you drink.

What happens when you drink?

Within minutes of taking your first sip, alcohol enters your bloodstream through your stomach wall and is circulated to every part of your body, including your heart, lungs, muscles and brain. It acts on nerve cells throughout your body and slows down the speed at which your nerves send messages to each other. The part of your brain that governs your judgement and self-control is affected first. That’s why your behaviour changes first, followed by your speech and finally your physical co-ordination.

If you drink one to two units of alcohol, you may find you become more talkative, feel more cheerful and relaxed, and get a warm feeling as your blood vessels relax, allowing more blood to flow around your body. But drink a couple more (four to six units) and you will start to feel light-headed and take longer to react.

If you drink more than eight units in one session, you may well find you have blurred vision, slur your words and find it difficult to balance or walk. You’re likely to feel ill and may get into situations where you feel vulnerable or risk harming yourself or others. If you really overdo it you are likely to vomit and/or pass out. This may result in problems with breathing and death.

The effects of alcohol on your mind

Alcohol is a depressant. Drink too much and your brain will have difficulty processing information. This means you may have trouble with:

• judgement and self-control
• seeing or hearing
• talking and walking
• remembering things
• sleeping – you’re more likely to wake up during the second half of the night and you may have difficulty getting back to sleep again

The effects of alcohol on your body

Your stomach

Alcohol irritates your stomach. Your stomach produces a strong acid to help break down the food you eat. A layer of mucous lines the stomach, oesophagus (the pipe that goes from your mouth to your stomach) and intestines to act as a barrier against this acid. Alcohol damages the mucous layer, allowing the acid to irritate the tissues underneath. If you drink too much alcohol, you’re likely to have heartburn, feel sick and have problems with flatulence, burping or belching.

Your heart

Alcohol makes your heart beat faster. This happens because your blood pressure drops when your blood vessels relax. To make sure your organs get all the blood they need, your heart has to work harder.

Your kidneys and bladder

Alcohol makes you produce more urine. If you drink too much, your body will try to get rid of the alcohol, mixed with water, in your urine. Not only will you need to make repeat trips to the toilet, but if you don’t top up with water or soft drinks, it will leave you feeling thirsty and dehydrated.

Your sexual organs

Drinking moderate levels of alcohol can increase your sexual desire and, by reducing tension, enhance your enjoyment. But drink too much and its effects on the nervous system can make it difficult for men to achieve or maintain an erection (often called ‘brewer’s droop’).

Your eyes and skin

Alcohol temporarily dilates (expands) the small blood vessels on the surface of your eyes, making them look red. It has the same effect on the blood vessels in your skin. Drink too much and you will have red eyes and feel hot and sweaty. In winter this may give a false illusion of being warm whilst the actual temperature of the body can fall dangerously.

Your liver

Your liver has many functions and one of them is to filter and clean your blood. It takes about one hour for your liver to clear a unit of alcohol from your bloodstream, although the exact rate depends on your age, weight and sex. The more you drink, the more you’re going to feel the effects of alcohol.

The morning after

The morning after an evening of heavy drinking, you can expect to have a hangover. A hangover is nature’s way of telling you that you have overindulged in alcohol. Symptoms of a hangover are due to the combined effects of alcohol on your body and mind. Typical symptoms include:

• a pounding head
• feeling thirsty
• feeling sick
• sensitivity to bright lights and loud noises
• red eyes and a dry, bloated and puffy face
• indigestion and mild diarrhoea
• tiredness and weakness

Worse still, you may not even be able to remember aspects of what happened the night before because alcohol can cause memory loss.

So all in all, the message is simple – it pays to drink alcohol sensibly.

For sources and links to further information, see Resources.