The medical term for a hangover is veisalgia, from the Norwegian word kveis which means “uneasiness following debauchery” and algia, the Greek word for “pain.” If you’ve ever had one, you don’t need a list of symptoms to provide you with a diagnosis: you’ll be all-too-familiar with the pounding headache, extreme thirst, nausea, diarrhoea and / or vomiting, lethargy, dizziness, and sensitivity to light and / or noise that follow a session of excessive alcohol consumption. Around twenty-five to thirty percent of drinkers don’t seem to suffer from hangovers at all, while people with allergies to wheat, barley, corn, or yeast tend to have the most severe symptoms. Your weight plays a role in how your body absorbs alcohol – the less you weigh, the more you’ll feel the effects of heavy drinking – while the older you are, the more intensely you’re likely to experience a hangover.
So what is it about drinking alcohol that results in such misery? The single main cause, according to medical experts, is dehydration. The ethanol in alcohol is a diuretic: it makes your body lose water by suppressing the release of the hormone vasopressin, which normally directs water released by the kidneys back into the body. Alcohol also causes inflammation of the stomach lining, which can result in further dehydration from vomiting or diarrhoea. The throbbing headache you have in the morning after a night of heavy drinking is due to your body ‘borrowing’ the water it needs from your brain, causing your brain to temporarily shrink away from the inside of your skull.
Excessive alcohol consumption also raises the production of stomach acids while slowing down the rate at which the stomach empties itself, resulting in nausea, vomiting, or stomach-ache, and the rapid drop in blood sugar levels (hypoglycaemia) can cause shakiness, fatigue, general weakness, and even seizures in some cases.
Everyone has a unique physiological response to alcohol in respect of how it’s broken down and eliminated by the body, and the way you metabolise alcohol has an effect on the onset, severity, and duration of your hangover. Alcohol is metabolised in two stages – one group of enzymes breaks ethanol down into acetaldehyde, which is a toxic carcinogenic substance; then another class of enzymes metabolises the acetaldehyde into harmless acetate (which is basically vinegar). In some people, the second metabolic process is slower and less effective which means a build-up of acetaldehyde toxicity manifesting in hangover symptoms like rapid pulse, sweating, nausea, and vomiting.
Another contributor to hangovers has to do with by-products of the distillation and fermentation process which are called congeners. Congeners are what give the distinct, full flavour to amber-coloured alcohols like whisky and rum but they also exaggerate hangover symptoms, which is why you’re less likely to suffer if you drink a clear ‘pure’ distilled alcohol like vodka. And anything with bubbles in it (whether it’s champagne, or Coke used as a mixer) speeds up the delivery of alcohol into your bloodstream: your liver can’t keep up, and you’re more likely to get a hangover.
There’s not much you can do to “cure” a hangover, though drinking plenty of plain tap water will help with the rehydration of your body and the flushing out of toxins. A spoonful of bicarbonate of soda in a glass of water can ease the queasiness and nausea, as can a cup of green or ginger tea. If your stomach can take it, the vitamin C in a glass of orange juice will help your liver break down the alcohol more efficiently while also raising your blood sugar levels.
Eating something simple may help: eggs, for example, contain cysteine which is thought to combat hangover symptoms, and bananas contain a natural antacid to ease nausea as well as magnesium to relax the blood vessels. Vitamin B-complex or a thiamine supplement is thought to replenish vitamins depleted by alcohol. If you can bear it, a little light exercise, preferably in the open air, raises your metabolic rate and helps your body clear out harmful compounds: the oxygen delivered to the cells of the body during exercise speeds up the detoxification process.
Be cautious with the use of over-the-counter painkillers: those which contain acetaminophen or paracetamol can interact with alcohol to cause liver damage, so it’s safer to choose aspirin or ibuprofen. If you’re in any doubt, consult your pharmacist. In the vast majority of cases, hangovers just have to run their course and symptoms will ease within about twenty-four hours.