Why hydration is good for your mental health

Jenna Farmer
By Jenna Farmer,
updated on Oct 29, 2021

Why hydration is good for your mental health

We all know about the importance of trying to drink our eight glasses of water a day, but there’s far more to it than just quenching your thirst…

If there’s one simple habit that’s universally recommended, it’s to keep on top of your water intake. Water is involved in so many different bodily functions – from helping our body get rid of waste to protecting our joints – yet in the busy lives we lead, many of us forget to drink enough.

Nutritionist Uta Boellinger says: “Good hydration is crucial for health and wellbeing, and just about every mechanism in your body relies on adequate water intake.”

It’s not just about your physical health either, with water playing a part in your mental health, too. A study found that drinking the lowest levels of water doubled the risk of depression and anxiety.

Let’s take a look at why keeping track of your hydration is one of the simplest and most effective things you can do for your mental health.

Why hydration is so important for our mental health

How exactly does hydration help our mental health? Well firstly, much of our brain is actually made up of water, so when we’re in a state of dehydration, our cognitive performance is affected. Studies have shown that just being dehydrated by 2% impairs things like memory and focusing on your daily tasks.

Because of this, reducing water intake can lower your mood too, since dehydration creates a stressor on the body – and may also impact mood-boosting hormones such as serotonin, that are found in our brain.

“Dehydration causes brain functioning to slow down and can impede serotonin production, as well as increase stress hormones, and that can contribute to making your mental health worse,” explains Claire Elmes, an emotional wellbeing consultant. “It can lead to lower energy, increased mood volatility, and poor concentration, exacerbating pre-existing symptoms, and leading to further discomfort.”


Another study found that those who reduced their water intake increased their thirst, which led to a decrease in positive emotions such as calmness and feeling content. In turn, those who had low levels of water and increased it, reported improved fatigue and an improvement in their mood when waking up at the start of the day. Clear evidence that not getting enough water could be one potential reason behind low moods and feelings of fatigue and low energy.

Why you might be at risk of dehydration

As well as understanding the importance of hydration, let’s talk about why you may be at risk of dehydration – particularly if you are dealing with mental health conditions such as anxiety and depression. One reason for this is that your mental health could be impacting your sleep patterns, which brings with it an increased dehydration risk.

Studies have shown that those who sleep for a shorter period of time each night, are more likely to be dehydrated.

This can sometimes create a vicious cycle: since we struggle to get enough sleep, we’re likely to be low on energy and reach for things like coffee and energy drinks to get us through the day. However, caffeine is also a known diuretic; this means it often increases your need to urinate after you drink it. Because of this, we lose more fluids through urination, meaning we need to drink even more water to compensate for this loss. Alcohol works in a similar way, so it’s also worth bearing this in mind. While it doesn’t mean you can never drink coffee and alcohol, it’s definitely worth drinking extra water to balance things out.

Finally, it’s worth considering that those with low moods might find it more challenging to track and keep on top of their fluid levels – something that’s really important in avoiding dehydration.

“When you’re struggling with depression, anxiety, or other mental health problems, it can be incredibly difficult to maintain a routine, and keep up healthy habits, like drinking plenty of water throughout the day,” explains Claire Elmes. “You may be preoccupied, forget, or lack the energy or will to look after yourself and nourish your body.”

How to maintain good hydration habits

The first thing that’s important is to understand the signs of dehydration, since some people don’t even realise they’re dehydrated. These include increased thirst, dry mouth, constipation, fatigue, and headaches. Some people also keep an eye on their urine when they go to the loo. Your urine should be a pale yellow; the darker it gets, the more likely you’ll need more water.

Don’t forget to consider energy levels, too. Nutritionist Uta Boellinger says: “If you’re feeling tired and struggling to concentrate, it can be a sign of dehydration. And your skin is also a good indication, especially dry, cracked lips which signal a lack of hydration.”

It’s also worth figuring out the right amount of water for you. We’re told eight glasses a day, but some people may need more than this – for example, those who exercise frequently or drink coffee regularly.

"Dehydration causes brain functioning to slow down and can impede serotonin production, as well as increase stress hormones, and that can contribute to making your mental health worse"

Create healthy habits to ensure you drink regularly: this could be setting hourly reminders on your phone, or using a water tracker bottle. Don’t forget that it doesn’t have to be just water you focus on. Your food intake may count towards your water intake too, with water-rich foods including watermelon, cucumber, and lettuce. In turn, if you find it tricky to drink plain water, adding fresh fruit or cordial can make it more palatable.

If it’s the case of just forgetting to drink enough, try to take steps to force the habit initially.

“Something I often suggest is to have a glass or bottle by your bed in the morning, so it naturally becomes the first thing you do,” says Claire Elmes. “Or make sure you always have a glass of water with a meal. By implementing these small changes to encourage yourself to drink more water, they can eventually become habitual (it can take up to a month, so don’t give up!) and you may notice slight improvements in your day-to-day functioning and mood, and your ability to manage your mental health.”

It’s clear that getting enough water each day is a simple yet effective habit that supports your physical and mental health. Keeping track of your intake, drinking regularly, and looking out for the signs of dehydration, can be a great way to make sure you stay hydrated and reap the benefits of a glass of water.

To connect with a nutritionist, or learn more about the effects of dehydration on mental health, visit nutritionist-resource.org.uk

Jenna Farmer

By Jenna Farmer

Jenna Farmer is a freelance health writer and nutritional therapist. She has Crohn’s disease and blogs about her journey to improve gut health.

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