A doctor's guide to beating the Christmas hangover

The Christmas season is here. You promised yourself that you’d take it easy, but then the odd tipple suddenly turned into a blurry mess. Now you’ve woken up with a few questionable selfies and 2023’s finest headache. We’ve all been there, right?   

Worst of all, your mouth is dry, your head is killing, and the slightest noise suddenly sounds like the Boeing 747 has flown straight overhead. So, what’s going on?   

The Christmas hangover – that’s what.   

Why do we get hangovers?  

Before we talk about what to do about hangovers, it’s worth understanding why they happen in the first place.   

Alcohol is a drug - and you’re withdrawing from it. Some people are luckier than others – about 10% of us are hangover-resistant. Sadly, the rest of us can suffer effects that last from a few hours to the whole day.   

Inside your body, there are biochemical and neurochemical changes going on that contribute to the hangover.   

Four reasons you get a hangover  

• 1. You’ve poisoned yourself 

When you drink, enzymes break down alcohol to form acetaldehyde - a poison and a carcinogen.  

Your body gets rid of it quickly, though some people have a genetic makeup that means the breakdown is slow. The slower it is, the worse you feel.   

This is particularly common in people of East Asian origin. Some of you reading this will know about Asian flush syndrome (AFS), which is redness of the face and a feeling of roughness that kicks in extremely quickly after an alcoholic drink.   

• 2. “What’s your poison?” Seriously 

Some darker alcoholic drinks like red wine and bourbon contain high quantities of chemicals called congeners. These are by-products from the fermentation process that add to the taste but also add to the hangover.  

• 3. Alcohol affects your brain  

Two important neurotransmitters are glutamate and gamma-aminobutyric acid (GABA). You can think of glutamate as the on-transmitter and GABA as the off-transmitter.   

Drinking alcohol stimulates GABA, which initially makes you feel relaxed and chilled, but soon it will also switch off areas of the brain responsible for judgement, inhibition, and, eventually, consciousness. At the same time, alcohol blocks glutamate receptors, meaning it becomes harder to lay down memories.   

• 4. You’re damaging your guts 

You’ve all seen those movies where the hero sterilises a wound with a nearby bottle of vodka. Well, they do that because alcohol kills organic material. That’s why alcoholic-based gels and sanitisers are so widely used.  

Unsurprisingly, if you tip alcohol into your guts, you will destroy your gut lining. This causes local inflammation, which leads to nausea and vomiting, and systemic inflammation, leading to headaches, confusion, tremors, and, eventually, depression and anxiety.    

The glutamate rebound  

Put all these changes together, and not only can you see what happens to you when you get drunk, but you can also start to see what’s happening in a hangover.   

When your glutamate receptors clear, your body increases its glutamate as it senses the imbalance. This glutamate rebound makes you exquisitely sensitive to light and sound. This probably also contributes to headaches, along with acetaldehyde, which causes swelling of the blood vessels in your brain, and dehydration - often exacerbated by the fact alcohol makes you go to the toilet (and possibly vomit) more.   

So, you have a sensitised brain that’s a bit swollen and isn’t being supported by a nice cushion of fluid around it. Add this to the inflammation of your gut lining, and you’ll probably feel sick and have some post-booze diarrhoea. Lovely.   

Now for the part that you’ve all been waiting for – what can we do to prevent the hangover?  

How to prevent a hangover  

Here’s the guaranteed solution: don’t drink. (Come on, I have to say this).  In the unlikely event that you don’t follow my advice, here are some more things to consider – both practical and psychological.  

Before you start drinking

• Eat - line the stomach with food. Not only will slightly less alcohol get absorbed, but you’ll protect the fragile gut lining.  
• If you're not home, prep for the journey home - have a warm coat, and make sure your phone is charged to get home safely (and so you can take some excellent drunken selfies).  

While you’re having a drink 

• Don’t go nuts – drink in moderation.  
• Take it slow – it takes about an hour to process one unit of alcohol. The slower you drink, the more chance you have to clear it.  
• Have smaller drinks – a single, a small wine, or half a pint.   
• Avoid drinks heavy in congeners – instead, have white wine and clear spirits.   
• Avoid the espresso martinis and Jägerbombs – not only will these keep you awake, but they’ll also make you need to urinate more, leading to more dehydration and more headaches. Buy one for the Insta photos, but don’t drink it.   
• Drink water - have a glass in between your drinks.  

Before bed

• Drink lots more water - have a glass, and then have another one by your bed for the midnight dry mouth.   
• Paracetamol – take a couple of these, it’ll probably help.   
• Antacids - if you are prone to reflux, take some antacids.   

The next day

• Water, water, and more water - I can’t emphasise this enough, but I’m sure trying. You will be dehydrated, so drink water like your headache depends on it. 
• If you can, take a duvet day - your brain’s neurotransmitters will thank you.  
• Have a decent breakfast - if you eat them, eggs are particularly tremendous.   
• Take paracetamol - if you have a headache, then some paracetamol and ibuprofen will help too. But don’t take ibuprofen if you already have a dodgy belly.   
• Book the day/night off – veg out in front of the TV - it’ll help your body return to normal.   

Things to avoid:  

There are a million and one internet cures out there for a hangover. A tremendous BMJ article from 2005 (see below) showed that these are not likely to work.   

Popular hangover myths 

• Hair of the dog - it doesn’t work and will simply delay the inevitable.  
• Coffee - yes, it’ll wake you up, but it’ll also make you more dehydrated. Headache here you come.   
• Sweating it out - exercise is normally great, but again you’ll dehydrate yourself and feel rough. If you’re going to exercise, make sure you have plenty of fluids. If you feel up to exercise, that is.  
• The massive fry-up - scientifically this won’t help you. But the smell and the feeling of grease, on a subconscious level, probably will.  
•  Going through your phone - eek!   

Have a great time and happy holidays!   

How to keep your liver healthy  

If you’d like to find out more about how to look after your liver, head over to our blog: seven ways to keep your liver healthy.    

We also talk you through relevant blood tests like our Liver Blood Test, which checks your liver function and helps you to sport early signs of inflammation.   

References

1. Interventions for preventing or treating alcohol hangover: a systematic review of randomised controlled trials.  BMJ 2005;331:1515  
2. The science behind hangovers — and what to do when you get one. Nutt, D. 2020 Ideas.Ted.Com https://ideas.ted.com/the-science-behind-hangovers-and-what-to-do-when-you-get-one-david-nutt/   
3. Hangovers. BMJ 2002;324:0206184