A hangover results from drinking too much alcohol. Those people with a low body weight, and therefore smaller amounts of body fluids, or a low ratio of fat to lean tissue, are most vulnerable. So are women and young people, who have smaller amounts of stomach enzymes to break down alcohol. The time and nature of the last meal also have an effect.

The principal cause of a hangover is dehydration. Alcohol is a diuretic, and loss of body fluid in the urine causes the classic symptoms of headache, nausea, vertigo and depression. Severity is largely determined by the amount and nature of the alcohol consumed.

Brandy, champagne and whisky contain congeners, which exacerbate the symptoms of hangover. Red wine contains tyramine, which causes headaches. Gin, vodka and white wine are the least likely candidates to cause a hangover so stick to these when possible.

Prevention is always better than a cure

1. Eat a good meal and drink a glass of milk before you embark on the consumption of alcohol. Fatty, oily foods will slow down the absorption of alcohol. Drink plenty of water with the meal.

2. Intersperse alcoholic drinks with soft drinks. This helps to prevent dehydration as well as moderating your alcohol intake.

3. Choose your drinks carefully, avoiding those containing congeners, and do not mix types of alcohol.

It's wise to drink more water before going to bed, preferably with a soluble tablet of vitamin C.

In the morning, avoid coffee and tea because the caffeine they contain is a stimulant and can exacerbate any jittery feelings. Also, drink plenty more fluids and preferably in the form of water, diluted fruit juice or skim milk. Anti-dehydration powders for diarrhea may also be helpful.

Eating, even a banana, will boost low blood-sugar levels, which may be causing irritability, dizziness and tiredness. Proprietary painkillers will relieve headaches, but curing a hangover with more alcohol should be studiously avoided.

Editor: Donald