angry baboon with a lump hammer has been using your head for target practice.

Your mouth feels like you've been sucking on ashtray-flavoured sweets all night, washed down with goldfish bowl water.

After you finally manage to stagger into the bathroom and look in the mirror, some idiot wearing a battered paper hat at a rakish angle is staring back at you. It's only then that you notice the small lumps of jelly in your ears.....

Welcome to the morning after. It's not a pretty sight.

Yet, it doesn't have to be this way. Understanding what causes hangovers and taking sensible precautions against getting one may prevent you from pleading with your nearest and dearest to do the decent thing and put you out of your misery.

In purely scientific terms, drinking lots of alcohol is like swallowing poison, and nature has decided the best way for your body to get rid of the poison is by making you feel like throwing up.

Headaches, extra sensitivity to light and sound, and the feeling of intense illness are all due to dehydration as alcohol drives fluid from the brain and the body.

Sometimes the hangover seems to bear no relationship to the amount of alcohol consumed. The problem here comes from what you drink and how you mix them.

Take for example fortified wines like sherry - a traditional Christmas tipple -which can give you a raging hangover. The culprits in these drinks are congeners. These give a golden colour to malt whisky and taste to sherry and port, for instance. A rough hangover guide is that the darker and sweeter the alcoholic drink, the more congeners it contains.

Top of the hangover table is port, closely followed by red wine, brandy and sherry. Whisky sits astride the half-way mark. Less likely to produce the horrors of a hangover are beer, lager and white wine, with gin and vodka being the least likely.

Okay, so that's the science lesson out of the way.

Now you need to know how to cope with that party night. Firstly, you need two plans of action. Plan `A' is all about prevention. Plan `B' is the one to bring into action if everything goes wrong and you wake up feeling like death.

Plan A. The cardinal rule is: never drink on an empty stomach. And if, before starting out, you can manage a large glass of milk, or a couple of spoonfuls of olive oil, then the food and milk (or oil) will help the stomach absorb the alcohol at a slower rate. The rest is up to your willpower...

While you are out at the pub, club or bar, try to drink water and eat something at regular stages during the evening. If you can match your alcohol consumption with water consumption you may have to pop to the loo more often, but at least you will not feel like a shrivelled prune in the morning.

When you do get home, try to drink a pint or two of water before going to bed.

If you're too far gone to remember this, then drinking the water when you awake is better than nothing.

PLAN B: If you blow it and do none of these things, what can you do? There are those who swear by the likes of Alka-Seltzer, while others reach for an aspirin. But be warned: aspirin is also a gastric irritant - and you want to soothe the stomach, not make it worse.

Black coffee? The caffeine in coffee will probably make you feel more perky for a short time, but it doesn't really solve the problem of How to cope dehydration.

What does have a good track record is the `prairie oyster' - which consists of a raw egg, beaten into tomato juice, with a splash of Worcestershire sauce.

This probably works by boosting blood sugar levels - and the egg will help line the stomach.

If you can't face that milk is a good alternative (obviously without the tomato juice and sauce).

Others swear by a cooked breakfast. Okay, so eating all that fat is not going to do much for your general health, but it can help take away the morning-after misery.

Time is the other great healer of hangovers. Your liver detoxifies alcohol at the rate of one unit, or half a pint of bitter an hour. Tiredness can make hangovers worse. Alcohol induced sleep is not as refreshing as undrugged sleep (rapid-eye movement sleep is depressed), so even after a 10-hour sleep one does not wake feeling well.

If all that fails, then there is one alternative guaranteed to stop you having a hangover. Don't drink! Alternate water with wine to avoid hangovers Christmas hangovers can leave your head feeling like a hot air balloon, luckily this one comes with a built-in cure