Research shows we endure post-party headaches and nausea for around 24 days a year - and many of these are during the festive season.

By Lisa Salmon.

In this season of general jollity your average partygoer will almost certainly be drinking a bit, or a lot, more than usual. And then facing the inevitable truth that the morning after the night before is no fun at all.

Recent research by food intolerance company Yorktest found people endure post-party headaches and nausea for a total of around 24 days a year, or 1,452 days in a lifetime.

And with a good chunk of those days popping up over the Christmas period, there could be a Santa sackload of misery on its way for many during the next few weeks.

Of course the best solution is to stay off the booze completely. But if that's not an option, then understanding why alcohol causes hangovers - and what can be done to reduce their impact - is a sensible way to ease those symptoms.

All too many of us will have experienced a headache, dry mouth, nausea, tiredness, dizziness - and even depression - the morning after.

GP Dr Roger Henderson explains that this, put simply, is because alcohol is toxic. "The body really doesn't like it, it's a big poison, which is why you can get alcohol poisoning," he says.

Think about dehydration Henderson points out that the driving factor behind hangover symptoms is dehydration. Alcohol acts as a diuretic, making you urinate more and thus lose water.

Even the brain loses some of its water, and the lining of the brain becomes inflamed, resulting in a pounding headache. This lack of water is also why you have a dry mouth and feel thirsty the morning after a big night.

"Try and alternate your alcoholic drinks with a non-alcoholic drink," advises Henderson.

"Ideally that'd be water, but any non-alcoholic drink is OK. If you're embarrassed about not being seen to keep up with the drinking, have a tonic water with ice and lemon, because that looks like you're having a gin and tonic."

Reduced blood sugar Alcohol can lead to alterations in the metabolic state of the liver, resulting in low blood sugar, according to Henderson. This can cause symptoms including feeling faint, tired, dizzy and wobbly the next morning.

Alcohol expert Professor Jonathan Chick, a consultant psychiatrist at Royal Edinburgh Hospital and author of Alcohol and Drinking Problems (Family Doctor Books, £4.95), says people can feel more energised while drinking, due to their blood alcohol levels going up.

However, by the following morning, in its absence, low blood-sugar levels caused by drinking will make individuals feel lethargic.

"You get a rebound," says Chick. "A feeling of tiredness, and sometimes of depression, which is what happens on the down slope of the alcohol curve. It's a sort of withdrawal symptom."

Don't go hungry Making sure you eat before and during the consumption of alcohol will help reduce hangover symptoms, and also mean you're less likely to be sick.

Chick explains that a lack of food when drinking can lead to vomiting. "Alcohol poisons cells throughout the body, and the first cells it hits are in the stomach lining," he says. So if there's no food in the stomach the poison will have direct access.

"It causes them to be reddened and inflamed, and some people even vomit blood during the night or the next morning because their stomach lining's so inflamed," he says.

"When food is taken, the alcohol's absorbed more slowly so high peaks aren't achieved and the body copes with breaking it down more easily."

Dark or light drinks?

A 2009 study by researchers at Brown University in the United States found the severity of a hangover is affected by the colour of the alcohol being drunk, with darker drinks, such as red wine or whisky, the worst offenders.

The study looked at how people felt and reacted the morning after drinking either bourbon or vodka.

Bourbon drinkers reported feeling worse than vodka drinkers, rating higher on scales that measured the severity of hangover malaise, including headache, nausea, loss of appetite and thirst.

However, it didn't mean vodka drinkers were completely unaffected the next day. Although they generally felt better, they performed just as poorly in next-day activities. The researchers found that all those who overindulged had slower reaction times, were less attentive, and found it harder to make decisions.

The study concluded that dark drinks contained more chemical by-products than lighter ones - bourbon, for example, had 37 times more chemicals than vodka - and these harmful by-products, called congeners, exacerbated hangovers.

"Congeners are quite toxic to the body, and they will worsen some of the typical hangover symptoms," explains Henderson.

"They're typically found more in the 'heavy' spirits, like cognac and brandy, as opposed to drinks like white wine which contain far less."

Hair of the dog No matter what you've been drinking the night before, having any alcohol, or 'a hair of the dog' the next day to relieve your hangover symptoms, isn't a good idea.

While it may reduce any hangover jitters you're experiencing, it won't help in any other way, says Chick.

"A very large amount of alcohol can the next day cause a mild version of what alcoholics know as the shakes," he explains.

"It's a kind of withdrawal symptom, and that's why some people feel better with the hair of the dog.

"But that would only help the jittery, nervous feeling, and it's a very risky path because it's the path towards establishing a serious chemical addiction."

Hangover help Dealing with a hangover depends on the symptoms, says Chick, but paracetamol or ibuprofen can help if you have a headache, and caffeine in coffee can give an energy boost if you're tired.

Eating will also help improve blood sugar and make you feel better.

"My own personal hangover cure is a full English breakfast," says Henderson. "But the ideal thing is something like toast with honey, because you get a slow release of sugar throughout the morning rather than a quick fix from something like pastries or cereal."

He also suggests eating baked beans and scrambled eggs on toast, because the beans and the bread will help to steady blood sugar levels, while eggs contain an amino acid called cysteine, which is thought to help mop up alcohol toxins in the body.

But the bottom line, stresses Chick, is to be mindful of your food and non-alcoholic liquid intake before and while you're actually drinking.

"If you're drinking alcohol, always take some food and add extra non-alcoholic liquids," he advises.

"It might not prevent you from having a hangover, but it'll definitely make you feel better."