How are you feeling now that the festive season is several days behind you? A bit under the weather? A bit low? Then don't blame it on the weather or the lack of sunshine. It could be that you are still suffering the after-effects of the alcohol you drank over New Year.

For one problem with drinking more than usual is that it has much longer-term effects on your body (particularly your liver and brain) than you think. Here's a quote from Enoch Gerber, head of the US National Institute on Alcohol Abuse and Alcoholism: "Even a single bout of drinking in a person who is clearly not an alcoholic can have serious effects on physiological functions for hours after alcohol has cleared the system".

That means for days afterwards you are much slower to react to emergencies when driving, for example. These "impairments" are not obvious to the drinker, who may think that because the headache has gone, all is back to normal. Even a night's sleep doesn't help much, because alcohol gives you a light anaesthetic that spoils normal sleep - giving you a post-anaesthetic state next day that can be very dangerous.

You may be negative on the breathalyser and have no alcohol in your blood, but you are still a danger. So if you have been on a binge, wait until you have been drink-free for two days before you think of driving again.

It's best not to binge at all. Whether you are a regular drinker or not, with the first drink - even the first sip - your brain adapts to the alcohol intake, so that the next drink has less effect on it. You begin to tolerate the alcohol more easily. This means that you quickly have to drink more to experience the kick you got out of the first drink.

That isn't an excuse to keep drinking - in fact quite the reverse. Because in the meantime the alcohol may be aggravating a stomach ulcer (very common in regular drinkers), or worsen a liver problem (like a hidden hepatitis), or even induce a heart attack.

Scandinavian researchers found that their high rates of heart attacks on Mondays were caused by binge drinking in the previous weekends.

Your head is another vulnerable part of the body when you drink. Obviously if you fall over you can injure it simply by banging it on the ground. But did you know that if you have alcohol in your blood when you do so, you are much more likely to bleed into your brain? The alcohol stops normal clotting in bruised blood vessels. That means you are at a much higher risk of a stroke than normal from a minor head injury.

So why do so many of us (who would never touch the stuff otherwise) drink over the holiday season? Psychiatrists say that most of us do it to ease anxieties about being with so many people socially. Alcohol shuts down a whole series of chemical processes linked to anxiety - which is why we are less inhibited than usual. That's dangerous in several ways.

One is if you are already taking other drugs to ease anxiety, like tranquillisers. Alcohol multiplies the effects of tranquillisers and vice versa, so that the combination can be disastrous - you become unconscious faster and have a much worse and longer hangover afterwards. That's if you are lucky enough to reach the hangover stage - there are plenty of people every year who don't.

So what about hangovers? The experts are still divided about what causes them. Some blame them on "congeners" - chemicals that are extra to the alcohol in drinks, such as red wines and spirits. Others point the finger at the alcohol itself - the more you drink the worse it will be. Yet others blame hangovers on the effects of spending the night in a noisy smoky room and having too little sleep.

Whatever the cause, the only real treatment for a hangover is to stay quiet in a dark room and drink plenty of water until the headache and sick feeling vanishes. You can prevent it, of course, by drinking much less the previous evening, and by alternating each alcoholic drink with a non-alcoholic one, so that you avoid dehydration.

But don't take painkillers for the morning-after headache. Aspirin may further upset your fragile stomach, and paracetamol will not do your liver, already reeling from its alcohol-induced battering, any good. You have to recognise that a hangover is the price you must pay for drinking too much, and you can only bear it until it gets better.

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.