What is a hangover?

A heavy head, over-sensitivity to light and noise, sickness and a raving thirst – hangovers make you wonder whether it was all worth it!


What causes a hangover?

A hangover is the consequence of drinking too much alcohol. Symptoms start when your blood alcohol concentration starts to get close to zero – in other words, only when the alcohol is almost cleared from your system will you start to feel the unpleasant effects.

What are the symptoms of a hangover?

The symptoms of a hangover are typically caused by dehydration, hormonal changes and the toxic effects of the alcohol you have drunk. They may include one or more of the following:

  • Fatigue and lethargy
  • Weakness
  • Excess thirst
  • Headache
  • Muscle aches
  • Nausea
  • Stomach upset
  • Vertigo
  • Sensitivity to light and sound
  • Anxiety
  • Irritability
  • Sweating
  • Elevated blood pressure

How long does a hangover last?

You can expect to experience symptoms for 24 hours, although it may take a little longer to feel like yourself again.

Discover more advice on alcohol, including Is low-alcohol beer healthy? And if you do over-indulge, check out our guide on hangover cures: fact or fiction and our ideal hangover recipes.

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With many of us enjoying a glass or two, follow our expert guide for how to prevent or cure a hangover…

Woman looking grumpy with head in her hand

How to prevent a hangover

1. Eat before you go out

Dairy foods, including milk and yogurt, are excellent stomach liners, so if you’re not going to be eating on your night out, enjoy a carton of plain yogurt with a banana, a bowl of cereal with milk or some cheese and biscuits before you venture out. Eating something slows the absorption of alcohol, otherwise blood alcohol levels may peak after just one hour of steady drinking.

During the evening, avoid salty snacks like peanuts and crisps – they’ll only cause you to drink more.

2. Limit fizzy alcoholic drinks

These really do go straight to your head – the bubbles speed up alcohol absorption, so limit the glasses of sparkling wine, fizzy cocktails and champagne.

3. Keep it clear

All alcohol can cause hangovers, but dark drinks (such as port or dark spirits) tend to be the worst offenders. This is because they contain congeners – chemicals which contribute to their taste, colour and aroma, but which break down in the body to form toxic compounds. Darker drinks, especially spirits like brandy or whisky, have higher levels of these congeners, so instead opt for clear spirits like vodka or gin.

4. Don’t mix

The amount of alcohol you drink in a given time frame is what determines how bad your hangover will be, but if you mix drinks, you’re more likely to drink more and have some drinks that contain hangover-inducing congeners. These toxins not only worsen your hangover but may increase stomach irritation too.

5. Avoid a nightcap

When we reach for a nightcap, it tends to be the darker spirits, like brandy or whisky, which have higher levels of congeners. So, if you must have a nightcap, choose a light-coloured spirit instead or better still, go without.

6. Before you call it a night, drink plenty of hydrating fluids

Glass of water

Dehydration is a major contributor to hangover symptoms, so ideally keep your water intake up between alcoholic drinks – this has two major benefits – it slows your drinking time and helps to mitigate the dehydrating effects of alcohol. Before you go to bed, have another large glass of water - drinking water at this point in the evening will help efficiently flush out toxins.

Hangover remedies

First up – there are no scientifically proven remedies for your hangover, but there are some things you can do to ease your discomfort.

1. Stay hydrated

The morning after, drink a sports drink or rehydration solution; this will help restore your hydration levels and replace the sugars and essential salts you may have lost. You can make your own rehydration drink by dissolving six level teaspoons of sugar and half a level teaspoon of salt in one litre of water and sip throughout the day.

2. Limit caffeine

You may be desperate for that pick-me-up but it’s best to moderate the number of caffeinated drinks you consume. That way you’ll benefit from some rehydration, an alertness boost and possibly even alleviate some of the withdrawal effects of alcohol.

3. Tuck in to breakfast

Pan of eggs and beans with peppers and coriander

It’s the best way to replace the vitamins and minerals your body will have lost while it worked overtime to process the excess alcohol. If you can’t face food, a bowl of breakfast cereal fortified with folate and iron should help to redress some of the damage and lift your energy levels.

Alternatively, if your stomach is up for it, opt for wholegrains such as a piece of wholemeal toast with a poached or scrambled egg, some grilled tomatoes and mushrooms and finish with a glass of vitamin-C rich orange juice.

Check out some of our delicious breakfast recipes.

4. Avoid painkillers

You may think they’ll sort out your head, but aspirin or ibuprofen will likely irritate your upset stomach further.

5. Resist sugar

You may find yourself craving a sugary fix, but don’t give in. Consuming sugary drinks and foods now will only prolong your disrupted blood sugar levels. Instead, reach for fresh fruit – it’s thought to help lessen a hangover’s intensity. Try our strawberry and banana smoothie.

6. Have a cold shower

With the appropriate precautions a cold-water shower, lasting about 1-3 minutes, may provide relief from some of your hangover symptoms. Studies suggest cold water immersion increases levels of adrenaline which makes you more alert and speeds up alcohol metabolism; cold water also raises levels of the feelgood brain chemical dopamine.

A word of caution, though, alcohol disrupts the temperature control centre of the brain, so be sure you are in the hangover phase, otherwise an additional drop in body temperature could put you at increased risk of hypothermia.

7. Gentle exercise

A full-on session in the gym is not going to help your alcohol detox, only your liver can do that, but some gentle exercise, preferably in the fresh air may clear your head and support your circulation. Walking or a gentle whole-body workout, such as yoga, may help you feel better – just remember to keep hydrated.

8. Should I supplement?

A number of studies suggest certain vitamins and minerals may have beneficial effects. They won’t cure a hangover, but they may help alleviate some of your symptoms. These include the B group of vitamins, vitamin C and the mineral zinc. It is always best to obtain these nutrients from food rather than supplementation, especially given marketed ‘hangover’ products may not have been assessed for safety and efficacy.

9. Avoid ‘the hair of the dog’

Have you been advised to take ‘the hair of the dog’? However well-meaning this advice may be, more alcohol is definitely not the answer. The theory here is that consuming more alcohol increases blood alcohol levels and as a result delays hangover symptoms. But it won’t make your symptoms any better and, more likely, it will make them worse!

Are some people more likely to develop a hangover?

Before you head out for the night it’s worth bearing in mind the factors that influence how quickly alcohol might affect you. These include:

  • Your gender
  • Your body size and build
  • The type of drink you choose
  • Whether you’re taking prescribed medication – antihistamines, for example, speed up alcohol absorption
  • If you’re female and of reproductive age, the stage of your menstrual cycle will also play a part. Alcohol is absorbed more quickly when you’re pre-menstrual and during ovulation.

Don’t forget government guidelines suggest men and women should drink no more than 14 units per week, so make sure you know exactly how many units are in your favourite alcoholic drinks.

Find more top tips from Drinkaware on how to drink responsibly.

Now read...

Hangover cures: Fact or fiction?
How many calories are in alcoholic drinks?
Is low alcohol beer healthy?

Kerry Torrens BSc. (Hons) PgCert MBANT is a registered nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including Good Food. Find her on Instagram at @kerry_torrens_nutrition_


All health content on goodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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