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Friday, 21 December, 2001, 23:52 GMT
What happens when you get drunk
It is Friday night, the end of a long week. You went out for a few drinks, ended up having a few more than that. Now it is Saturday afternoon and you are still feeling lousy.

What happens to your body after drinking steadily over six hours depends on the amount you drink, how fast you drink it and your body's tolerance to alcohol.

But BBC News Online talked to Professor of clinical biochemistry Timothy Peters of King's College London about the likely impact that a night on the town has on your body.

The first few hours after drinking:

One of the most rapid affects of alcohol is on the central nervous system (CNS), which controls a range of vital body functions not least the sense organs, muscles controlling speech as well as the sweat glands in the skin.

Under normal circumstances the CNS receives sensory information from organs such as the eyes and ears, analyses it and then initiates an appropriate response such as contracting a muscle.

But intoxication interferes with the CNS ability to analyse sensory information resulting in the typical symptoms of being drunk such as disturbed balance, slurred speech, blurred vision, heavy sweating and the dulling of our sensation of pain, which is why alcohol in the past was used as an anaesthetic.

High alcohol consumption can disrupt the brain's judgement of distances and heights

Alcohol also affects the outer layer of the brain, the frontal cortex, the region concerned with conscious thought which is why people under the influence of alcohol often lose their inhibitions.

Alcohol is also a diuretic, as it stops the production of the body's anti-diuretic hormone.

The kidneys direct fluids straight to the bladder, making you urinate excessively and speeding up the loss of fluid from the body causing dehydration.

Most of the nasty symptoms of a hangover including headache, dizziness, thirst, paleness and tremors are caused by dehydration.

Alcohol also affects the cerebellum in the brain which controls balance and coordination as well as eye movements.

Therefore high alcohol consumption can disrupt the brain's judgement of distances and heights and cause dizziness.

Alcohol has a battery of negative effects
The liver is the main organ that gets rid of alcohol by breaking it down.

It metabolises about 90% of the alcohol in our body while only about 10% is excreted through either our urine or breath.

The liver metabolises alcohol, at the rate of one to two units per hour.

A unit of alcohol is equivalent to half a pint of beer or lager, 25mls (a standard shot) of spirits in a pub or 125mls of red or white wine.

When a person drinks the body responds to large quantities of increased glucose in the system by producing more insulin which removes the glucose.

Once the process has started, the insulin carries on working removing glucose from the blood.

Low blood glucose levels are responsible for that shaky feeling, heavy sweating, dizziness and blurred vision. Low glucose levels also result in feeling tired.

To overcome this feeling of lethargy and tiredness the body will be craving a carbohydrate boost which is why many people feel hungry when they have been drinking.

A Few Hours Later:

Although people often seem to crash out and sleep after drinking, there is evidence to show that after drinking people's quality of sleep will be effected through dehydration.

People are still likely to feel tired after sleeping following drinking as they will have missed out on quality sleep

Alcohol also interferes with sleeping rhythms.

Therefore, even though someone who has been drinking might look as if they are crashed out, they will not be getting the deep sleep that is needed to recharge their batteries.

People are still likely to feel tired after sleeping following drinking as they will have missed out on quality sleep.

Alcohol relaxes the pharyngeal muscles, in the back of the mouth, increasing the likelihood of snoring.

The Next Day:

The liver is still breaking down alcohol in the body and therefore a breathalyser test could still be positive in the morning.

Alcohol plunders our stores of vitamins and minerals, which need to be in the correct balance for the body to function normally

The toxicity of alcohol can irritate the stomach causing gastritis (chronic stomach upset) often resulting in retching and vomiting.

The toxic effect of alcohol can also cause inflammation of the oesophagus, the tube that carries food from the throat to the stomach, causing heartburn.

Alcohol often affects the large bowel. The small and large intestine reabsorb salt and water but alcohol interferes with this process often causing diarrhoea.

Alcohol plunders our stores of vitamins and minerals, which need to be in the correct balance for the body to function normally.

It seriously disturbs the appropriate balance of minerals in the blood including potassium along with calcium, and sodium which are known as ions, is maintained by the kidneys.

The level of each ion must be maintained within narrow limits but dehydration caused by drinking, can affect the concentration of ions by draining potassium from the body, resulting in thirst, muscle cramps, dizziness and faintness.

The liver needs water to get rid of toxins from the body but as alcohol acts as a diuretic there will not be sufficient amounts in the body, so the liver is forced to divert water from other organs including the brain which causes the throbbing headaches.

Not only is alcohol toxic but the liver also produces more toxins in the body as a by-product during the breaking down process of alcohol.

When the liver is metabolising alcohol it produces acetaldehyde, a vinegar like substance which has toxic effects on liver itself, the brain and the stomach lining, resulting in severe headache, nausea, vomiting and heartburn and the feeling of being unwell.

Our bodies produce enzymes to attack these toxic agents but they only work at set rates thus the accumulation in our body caused by excess drinking and the build up that remains in our body the next day, makes us feel ill.

See also:

28 Nov 01 | Health
Drinking 'may help conception'
15 Apr 01 | Health
Why alcohol affects women more
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