Too much year-end partying and over-consumption of alcohol can bring on that proverbial hangover, as sales executive Marc Lee found out.

The late nights, lack of sleep and over-eating too can all take a toll on the body.

Mr Lee, 26, found this out the hard way last year when he had to juggle work with year-end festivities organised by friends and colleagues.

He had been to eight parties within two weeks, all with food and drink aplenty. In the party mood, he partook without giving much thought to the consequences.

As a result, he was mentally and physically exhausted by New Year's Day.

"I had a constant hangover. I was enjoying myself at night but I was very cranky and inattentive at work during the day," he recalled.

So what happens to your body when you over-indulge during the festive season? Mind Your Body spoke to some doctors to find out.

Hangovers
Alcohol can loosen people's social inhibitions and allow them to have fun. However, it can also lead to a nasty headache in the morning, mostly due to its dehydrating effects. It can also make people drunk.

As we drink alcohol, our liver starts to metabolise, or convert, the ethanol (that is, alcohol) into acetaldehyde with the help of special enzymes, said Dr Adeline Ngo, a consultant with the department of emergency medicine at the Singapore General Hospital (SGH).

This acetaldehyde, which intoxicates us, has to be converted by the enzyme acetaldehyde dehydrogenase into the more harmless acetic acid.

We get drunk, Dr Ngo said, when the liver cannot metabolise the amount of alcohol consumed quickly enough.

She added that more than half of Asians have insufficient amounts of acetaldehyde dehydrogenase, hence the flushed or red faces due to acetaldehyde build-up.

Women tend to have lower levels of dehydrogenase than men, which explains why they may get intoxicated more easily.

Habitual drinkers may develop a greater tolerance for alcohol. However, this is nothing to boast about as habitual binge-drinking can eventually lead to conditions like alcoholism and liver problems.

Some symptoms of a hangover are nausea, headaches, fatigue and diarrhoea. As alcohol affects mood, it can also cause irritability and anxiety in those who are hungover.

Dr Ngo said some people believe eating food before drinking may help dilute the alcohol in their stomach, thus reducing its effects.

Others believe that fatty foods (like dairy and meat products) or taking vitamin B pills will help. She added that these popular methods to stave off a hangover have not been proven to work for everyone.

In her work at SGH, she sees a spike in intoxication-related cases during the festive seasons. The best way to prevent a hangover is to avoid drinking altogether, she said.

Exhaustion
Poor sleeping and eating habits during this season can lower one's immune protection, said Dr Rupert See, senior physician at Raffles Medical. This can make one more susceptible to conditions like flu, gastritis and tension headaches.

The good news, however, is that the body should recover quite well once it returns to its normal cycle of eating and sleeping.

From a traditional Chinese medicine (TCM) perspective, lack of sleep can put one's body out of balance, thus leading to poor health. "Insufficient sleep can deplete one's yin (which represents bodily fluid), which causes internal heat," said senior physician Yu Zhe Kai of the Eu Yan Sang TCM clinic at Plaza Singapura.

He added that those with insufficient sleep tend to be tired, thirsty and easily irritable. "Their blood pressure and sugar level may also go up. For people suffering from hypertension or diabetes, insufficient sleep may also worsen their condition," he said.

Mental stress
Festive excesses can also lead to psychological stresses. With many work and family-related social gatherings to attend, the sense of having to live up to other people's expectations can be a mental strain, said psychiatrist Dr Brian Yeo.

Introverted people may try to put on a cheery front, while others may feel the social need to be friendly to family members, colleagues or bosses they dislike.

Such stress may be made worse by all the smoking and drinking going on, Dr Yeo added.

Combined with other factors like the lack of sleep, many get a burnt-out feeling by the end of the holidays.

"If you are already feeling low, alcohol can make you more depressed," Dr Yeo said.

Get over that hangover - quickly
Too many late nights spent eating and drinking can lead to a hangover and exhaustion - both physically and mentally. So how do you speed up your recovery from a festive burnout? Mind Your Body spoke to the experts to find out.

1 Have another fix?
Bartender Jett Koh, 32, has heard of all kinds of folk remedies over the years from her customers at Muddy Murphy's Irish Pub.

She said these supposed "fixes" mostly involve either Bloody Mary cocktails (a mix of vodka and tomato juice) or a "hair of the dog" - yet another drink of whatever the person had the night before.

One concoction which supposedly cures headaches, she said, is a mix of Angostura bitters (a sort of pungent herbal beverage) and lime cordial.

However, she felt that remedies involving alcohol only put off a potential hangover till later.

To avoid a hangover altogether, her own advice is to drink in moderation and to have lots of water in-between drinks.

2 Eating right
Besides water, drinking fruit juice is a good idea as it contains vitamin C and antioxidants which strengthen the liver, said Dr Rupert See, senior physician at Raffles Medical.

Fructose in fruit juice, he said, can help increase the speed at which the body processes alcohol.

He added that the amino acids found in protein-laden food such as scrambled eggs can assist in the body's detoxification process.

Brown toast, which is high in vitamin B, and honey can also help raise blood-sugar levels to fight fatigue and to take away any jitters after a night of heavy drinking.

3 Medication
Medicines like paracetamol or aspirin can also be used to relieve hangover symptoms like headaches.

For those suffering from indigestion or heartburn, simple over-the-counter antacids can help as well, said Dr See.

4 Exercise
You may not feel up to it but some light exercise can help you along in your recovery.

Personal trainer Joan Liew suggests 20 to 30 minutes of brisk walking or light jogging to help re-energise your body. Swimming, too, can be a low-impact and relaxing way to recover.

If you have access to a gym, a light workout routine, lasting about 45 minutes to an hour, that exercises your major muscle groups can get your blood circulating again and boost your energy, she said.

Whatever the activity, remember to keep well-hydrated, especially if you have been drinking heavily the night before, she added.

5 Herbal remedies
Prepared as a drink, an American ginseng and chrysanthemum mix can help restore one's energy after a late night out, said senior physician Yu Zhe Kai of the Eu Yan Sang Traditional Chinese Medicine (TCM) clinic at Plaza Singapura.

He said American ginseng can help replenish the body's vital energy, or qi, and the chrysanthemum can help reduce the body's internal heat accumulated due to lack of sleep.

Acupuncture can promote blood circulation and strengthen the body's flow of qi, he said.

For hangovers, a tea concoction comprising a mix of pueraria flower, Japanese raisin tree seed, bamboo shavings and lalang grass rhizome can help stop headaches and nausea.

In addition to "cooling" the body, this mixture also helps the body to discharge toxins through diuresis or the increased passing of urine.

Other herbal hangover remedies include mung beans and a vinegar drink that consists of white sugar and cooking vinegar. This latter concoction can help neutralise the alcohol consumed and help one sober up faster, Mr Yu said.

This article was first published in Mind Your Body, The Straits Times, on December 25, 2008.