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Immediate effects of alcohol on the brain and body

The first few drinks affect judgment and reaction time.
More alcohol causes reactions to become even more sluggish and delays physical coordination.
Far too much alcohol can suppress some body functions and, in extreme cases result in death.

The physical effects of alcohol

From the second you take your first sip, alcohol starts affecting your body and mind. After one or two drinks you may start feeling more sociable, but drink too much and basic human functions, such as walking and talking become much harder. You might also start saying things you don’t mean and behaving out of character. Some of alcohol’s effects disappear overnight – while others can stay with you a lot longer, or indeed become permanent.
If you’ve drunk heavily the night before, you’ll almost certainly wake up with a hangover. Alcohol irritates the stomach, so heavy drinking can cause sickness and nausea and sometimes diarrhoea. Alcohol also has a dehydrating effect, which is one reason why excessive drinking can lead to a thumping headache the morning after.


Drinking too much alcohol isn’t good for your skin either. As well as causing bloating and dark circles under your eyes, alcohol dries out your skin and can lead to wrinkles and premature aging. If you drink heavily you may develop acne rosacea, a skin disorder that starts with a tendency to blush and flush easily and can progress to facial disfiguration, a condition known as rhinophyma.

Alcohol poisoning

In the worst cases alcohol poisoning can cause lung damage (as you inhale your own vomit) and even lead to a heart attack.
Many traditional ‘cures’, such as drinking black coffee; just don’t work – or even make things worse.

Diseases and cancers

Liver disease
Liver disease used to affect mainly drinkers in middle age, but now sufferers are getting younger. Up to one in three adults drinks enough alcohol to be at risk of developing alcohol-related liver disease.


Alcohol misuse is an important factor in a number of cancers, including liver cancer and mouth cancer, both of which are on the increase. Alcohol is second only to smoking as a risk factor for oral and digestive tract cancers.
Evidence suggests that this is because alcohol breaks down into a substance called acetaldehyde, which can bind to proteins in the mouth. This can trigger an inflammatory response from the body – in the most severe cases, cancerous cells can develop.

Pancreatitis and diabetes

Chronic pancreatitis is another disease associated with heavy drinking. It’s caused when your pancreas becomes inflamed and cells become damaged. Diabetes is a common side effect of chronic pancreatitis. There’s evidence that heavy drinking can reduce the body’s sensitivity to insulin, which can trigger Type 2 diabetes.
For more information read our Alcohol and pancreatitis factsheet and Alcohol and diabetes factsheet.

Heart disease

While studies suggesting that alcohol can help heart disease often hit the headlines, the reality is that the jury’s still out on the extent of any benefits. And it is clear that any benefits which there may be are limited to very low levels of consumption – probably no more than 1 unit alcohol per day.

Mental health

Alcohol alters the brain’s chemistry and increases the risk of depression. It is often associated with a range of mental health problems A recent British survey found that people suffering from anxiety or depression were twice as likely to be heavy or problem drinkers.

Extreme levels of drinking (defined as more than 30 units per day for several weeks) can occasionally cause ‘psychosis’, a severe mental illness where hallucinations and delusions of persecution develop. Psychotic symptoms can also occur when very heavy drinkers suddenly stop drinking and develop a condition known as ‘delirium tremens’.

Heavy drinking often leads to work and family problems, which in turn can lead to isolation and depression. For heavy drinkers who drink daily and become dependent on alcohol, there can be withdrawal symptoms (nervousness, tremors, palpitations) which resemble severe anxiety, and may even cause phobias, such as a fear of going out.


If you drink large quantities of alcohol on a regular basis you run the risk of becoming addicted. This can have serious effects on their families, friends and partners, as well as their mental health.