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“Can dehydration affect your sleep?” A sleep expert answers your questions

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Welcome to Stylist’s Sleep Diaries, where we’re taking a deep-dive into one of the most important (and elusive) factors in our day-to-day lives: sleep. To help us understand more about it, we’re inviting women to track their bedtime routines over a five-day period – and presenting these diaries to sleep expert Dr Nerina Ramlakhan for analysis.  

In this week’s Sleep Diaries, a 20-year-old account manager learns about the surprising impact her water-drinking habits could be having on her sleep.

A little about me:

Age: 20

Occupation: account manager

Number of hours’ sleep you get each night: 6.5 hours

Number of hours’ sleep you wish you got each night: 9 hours

Do you grind your teeth/have nightmares: yes to both

Do you measure your sleep in some way (eg using your phone or wearable): I use the app Pillow

How much water do you drink on average per day: less than a litre

How much exercise do you do on average per week: none

Day 1

After leaving work, I head straight to see my friend. She’s house sitting and I thought it would be nice to give her some company, so we go to the Co-Op to grab some bits for dinner: homemade spaghetti bolognese, a slice of cheesecake and a few glasses of wine in front of the TV.

I have a little bit of anxiety about sleeping in a strange place, so when I get into bed I pop the electric blanket on and take zopiclone (a sleeping pill). A few minutes later I’m asleep and I wake up about half an hour before my alarm.

My friend offers me breakfast, but I decline because I’m conscious I need to get to work – it’s a 30-minute drive via a toll bridge.

Day 2

I eat dinner when I get home from work around 7pm before having a hot shower and putting my pyjamas on. I spend the rest of the evening lying on my bed with the TV on in the background while scrolling on TikTok – I’m waiting for the go-ahead from a big client and can’t stop thinking about it.

Once I switch the lights off, I have a broken night’s sleep, and I spend most of the night tossing and turning until 4am, when I cave in and put the TV on in the background. 

Day 3 

I get up at 7.30am because I’m working from the office today. I’m feeling tired and decide to wear a tracksuit to work so I’m comfortable.

I’ve been having strange dreams at the moment, and I wake up feeling like I’m being chased – might have something to do with the fact that I watched The Walking Dead before I fell asleep.

I also notice my Invisalign aligners are about to break at the back because I keep grinding my teeth in my sleep.

I have a cup of coffee and a protein yoghurt for breakfast, after which I don’t reach for any water until 3pm.

By the time the evening comes, I eat dinner and then crawl into bed, where I take a sleeping pill.

A woman watching tv in bed
“I’ve been having strange dreams at the moment and I wake up feeling like I’m being chased – might have something to do with the fact that I watched The Walking Dead before I fell asleep.”

Day 4

The business I work for is a start-up, so my job involves a lot of overtime and endless cups of coffee – especially at the moment.

Once I’m finally finished with work for the day I eat a chippy tea with my family for dinner before taking a shower, planning my outfit and lunches for the next day and catching up with some Netflix.

I leave the TV on in the background to drown out the background noise as I wind down – I live at home with my parents and can always hear my family coming up and down the stairs.

I’m still not fully recovered from the other night when I failed to get to sleep until 4am, so I’m really looking forward to a weekend lie-in. As I close my eyes I realise I haven’t had a drink of water all day.

Day 5

It’s Friday today, so I feel more relaxed at the office and can leave a little earlier than usual.

Once I’m done I head home to unwind and pop open a bottle of pinot grigio, which I end up drinking two glasses of. I don’t eat any dinner because I’m feeling pretty exhausted, but I don’t feel too worried about how I’m feeling as there’s no morning alarm.

I wake up naturally around 9.30am and have a tiny headache.

So, what does it all mean? A sleep expert offers her thoughts

Dr Nerina Ramlakhan, sleep expert and professional physiologist, says: “I’m not surprised you’re not sleeping well – you’re breaking most of my cardinal rules. You’re clearly a sensitive sleeper and, as such, need to up the self-care if you want to get the sleep you need and deserve. You’re taking sleeping tablets – zopiclone – but these pills will become addictive and will stop working after a time.

“Where do we start? I would advise you to go for some quick wins – you really need to up your water intake. Set a timer and aim to drink at least two litres of water a day. Dehydration affects your sleep and your energy levels. In order to get deep restorative sleep, your brain biochemistry needs to be optimal, and this means getting your hydration right. You’re definitely dehydrated, and the electric blanket isn’t going to help this. A small change that can make a big difference.”

Dr Nerina Ramlakhan Stylist's sleep expert
Sleep expert Dr Nerina Ramlakhan

Dr Nerina continues: “Where to next? Social media out of the bedroom please! It’s overstimulating your nervous system, as is your choice of TV viewing – you need to go to bed feeling safe (please check out my latest book Finding Inner Safety). I’m not surprised you’re waking up with nightmares – I would too!”

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If you would like to take part in Stylist’s Sleep Diaries, please email with your name, age and any sleep problems you’re dealing with, using ‘SLEEP DIARIES’ as the subject. We look forward to hearing from you.

Lead image design: Ami O’Callaghan

Other images: Getty/Dr Nerina Ramlakhan

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Lauren Geall

As Stylist’s digital writer, Lauren Geall writes on topics including mental health, wellbeing and women’s issues. She’s also a big fan of houseplants and likes to dabble in film and TV from time-to-time. You can find her on Twitter at @laurenjanegeall.

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