Tolerance to Alcohol

If a person drinks regularly, there will be a gradual lessening of the noticeable effects of alcohol. This is called an increased tolerance to alcohol; more alcohol is consumed to experience a "buzz". Irrespective of tolerance, alcohol is still entering the blood stream and blood levels are no different to those of less tolerant people (of the same weight and body fat) who drink the same amounts. Tolerance is not a protection against physical harm; in fact, increased tolerance may place a person at risk of drinking at harmful levels.

Safe drinking limits

One unit of alcohol = 1 pub measure of spirits, or a small sherry, or 1 standard glass of wine, or ½ a pint of normal strength beer, lager or cider. Remember, a pint of strong beer, lager or cider can contain up to 5 units of alcohol.

The recommended safe limits are 14 units for women (e.g. 7 pints or 14 pub measures of spirits), and 21 units for men (10 ½ pints or 21 pub measures of a spirit) with one or two alcohol free days a week. Women drinking between 15 and 21 units, and men drinking between 22-35 units are advised to cut down. Women drinking over 21 units and men drinking over 35 units a week are risking serious damage to their health.

There is however, no safe limit for drinking and driving. The risk of having an accident increases once there is alcohol in the driver's body. Even just below the legal limit, a driver may be up to 5 times more likely to have an accident, than if s/he had not had a drink.

The legal limit for drinking and driving in the UK is 80 milligrams of alcohol per 100ml of blood, 35 micrograms per 100ml of breath, or 107 milligrams per 100ml of urine.

So a man of average size (10-12 stone) is likely to be over the legal limit for driving one hour after consuming five units of alcohol e.g. 2 ½ pints or 5 pub measures of spirits. A woman of average size (7-10 stone) is likely to be over the legal limit for driving one hour after consuming three units of alcohol e.g. 1 ½ pints or 3 pub measures of spirits.

Is there anything wrong with a drink now and then?

It all depends what you mean by "a drink" and what you mean by "now and then". A small amount of alcohol does you no harm and can be enjoyable. It may even be good for your health.

But if it is more than a small amount and it's a regular thing, then maybe you shouldn't be taking your drinking for granted. Maybe it isn't quite as harmless as you think it is.

Drinking is best when you don't over do it. Drinking too much alcohol - or even drinking a little at the wrong time - can cause problems. Not just hangovers, but accidents - at home, at work and on the road. And it can do serious damage to your health, to your family and to your self-esteem - and also your pocket.

Who's at risk?

If you drink at all, you're affected by alcohol. Generally, if you only drink a little, the risks to your health are very small. But the more you drink, the greater the risks. You also put yourself and others at risk if you drink inappropriately, for example by drinking and driving. That's why it is important to look carefully at your drinking habits. This guide will help you to find out if you are a sensible drinker, and tell you what to do if you feel that your drinking is becoming a problem.

How much alcohol is in my drink?

The most important thing that you need to know is the amount of alcohol in your drink, and how the different drinks compare in strength.


Each of the following drinks, in standard pub measures, contains roughly the same amount of alcohol, a "unit".

Half-pint of ordinary strength beer, lager or cider;
One small glass of wine;
One single measure of spirits;
One small glass of sherry;
One single measure of aperitifs;

There are approximately eight units in a 75cl bottle of wine, eleven units in a 1 litre bottle of wine, 13 units in a bottle of sherry and 30 units in a bottle of spirits.