Day 5: Is dehydration causing your mood swings?

10 (10 reviews) Rate this page

Qualified Life Coach
Ask a question

10 November 2017

How dehydration affects mood

Being even mildly dehydrated can cause fatigue, difficulty concentrating, headaches and alterations in mood and mental function. Research has found that dehydration makes us more prone to feeling angry, anxious and irritated.1 The study found that women were more likely to experience alterations in mood whereas men were more likely to struggle with mental tasks, memory and feel more anxious and tense. 

It is thought that dehydration causes anger and mood swings because of a less efficient blood flow to the brain. Another possibility suggests that the neurons in the brain can detect dehydration and then signal parts of the brain that regulate mood.

Balanced electrolytes, balanced mood

When we are dehydrated we are more likely to experience an imbalance in our electrolyte levels which, in turn can also impact our mood. These levels tend to alter when water levels in the body change, for example when we sweat during exercise. Electrolytes are small slightly charged particles that are needed by our body for a wide variety of functions. They can be found in our diet and in the foods that we eat. A few of the main electrolytes include: sodium, potassiummagnesium and phosphate. While these electrolytes are involved in a number of essential bodily processes such as muscle function and fluid regulation, they are also connected to our mood as well.

One study found that a low-sodium, high-potassium diet had a beneficial effect on depression, tension and overall mood.2 Magnesium, which has also been called ‘the original chill pill’ is involved in over 300 chemical reactions in the body, and is responsible for helping to regulate our mood and prevent fatigue. Magnesium also plays a major role in calming the nervous system by blocking N-methyl D-aspartate receptors (NMDA) which inhibits excitatory neurotransmission.3

What’s more, when we are stressed our body creates a stress hormone called cortisol which causes a cascade of physical effects – all of which use up the magnesium already in the body.4 There have been a few studies into the effects of magnesium on depression with promising results; one study claims that magnesium helps to lift depression by raising the levels of our mood-boosting neurotransmitter serotonin.5

Being deficient in any of these electrolytes can wreak havoc not only on our body but on our mental well health too. Dehydration and loss of electrolytes can occur through sweating, diarrhoea and vomiting. It is essential for our health and our mood that we replace these electrolytes when we can. They can be found in our diet as well as some electrolyte drinks. If you opt for an electrolyte drink I would always recommend one that is made from natural ingredients and doesn’t contain excess sugars such as our own Balance Mineral Drink which contains magnesium, zinc, potassium, calcium and vitamin D.

The worst drinks for your mood


Alcohol can affect your mood in a variety of ways and the more you drink the more likely you are to experience these negative effects. Alcohol is a depressant, meaning that it slows the function of the central nervous system and can cause low mood. Drinking regularly lowers the levels of serotonin in the brain (a chemical that helps to regulate mood). Many of us drink alcohol to relax but, actually, it can increase in anxiety and stress rather than reducing it. While one glass of wine after a hard day can help you to relax, drinking large amounts excessively can interfere with the neurotransmitters in our brain which are needed for good mental health.6

Alcohol is also a diuretic, meaning that it causes us to urinate more frequently than normal. This excessive urination can then cause dehydration, which, as we know, can wreak havoc on our mental wellbeing.

This doesn’t mean that you should stop drinking altogether, but moderation is key and it’s important to be mindful and aware of the full effects it can cause.

Fizzy drinks

An obvious one here perhaps, but sugary drinks are another culprit for mood swings. When we drink sugary drinks we get an instant energy boost and spike in our blood sugar levels. Afterwards, we get that well-known crash and drop in blood sugar which causes tiredness, irritability and mood swings. This drop in blood sugar can also leave us feeling anxious, moody or depressed.

What’s more anything sugar-loaded, whether it’s food or drinks, can mess with our neurotransmitters that are responsible for keeping our mood stable. When we consume sugar, we stimulate the release of our neurotransmitter serotonin. Constantly eating sugar can result in the over-activation of serotonin release, this over-activation can deplete our limited supplies and contribute to symptoms of low mood and depression.7


Caffeine works by stimulating the central nervous system and releasing adrenaline and norepinephrine which are involved in our body’s fight-or-flight response. This response is a survival reaction which is useful in life threatening situations, but not so much if you’re sitting having a coffee with friends! The alertness caused by the caffeine can result in negative mood fluctuations, agitation and anxiety.

However, although caffeine can have a negative effect on mood and cause symptoms such as anxiety research is now indicating that caffeine may be beneficial for conditions such as depression. One experiment found that the chemical effects of caffeine can prevent brain receptors from responding to stressful situations. This means that stressful responses, such as low mood or depression, are less likely to take hold.8

Again, I’m not saying that you should cut out the caffeine altogether, after all who doesn’t like a little pick-me-up now and then? But, it is important to find balance, meaning that you shouldn’t go crazy on the caffeine either!

Around 400 mg is the recommended amount of caffeine that we should be taking daily. This adds up to roughly the amount of caffeine that is found in 4 cups of coffee. If you are used to drinking more than this I would suggest switching out for a caffeine free alternative such as Bambu.

How will I know if I’m dehydrated?

There are a few ways your body tries to tell you that you’re dehydrated:

• Feeling thirsty

• Urine colour – dark urine tends to indicate that you are dehydrated whereas lighter yellow urine indicates sufficient hydration

• Headache

• Fatigue

• Mood swings, feeling angry or irritated

• Feeling hungry

How much water should I drink to avoid dehydration?

Generally it is recommended that we drink between 6 to 8 glasses of water a day. This might seem like a lot - especially as water isn't particularly exciting! The good news is there are a couple of ways that you can make your water a little bit more appealing. Adding fruit or herbs such as cucumber, strawberries, and mint into your water can give it more flavour. Why not have a go at making our Lemon, Mint and Cucumber Detox Water?

How else can I prevent mood swings?

Mood swings affect all of us at one point or another, there are many factors that contribute to mood swings so, unfortunately, there isn’t a definitive way to stop them from happening. However, there are steps you can take to help prevent the longevity and severity of them:

• Exercise – physical activity is a great way to help lift mood and relieve stress

• Herbal remedies – herbal remedies such as St John’s Wort can help lift low mood and help us cope with life’s challenges

• Diet – our diet can play a big role in how we feel, making sure we have a balanced diet containing plenty of vitamins and minerals will help prevent fatigue, irritability and mood swings.


A.Vogel Hyperiforce St John's Wort Tablets used to relieve the symptoms of slightly low mood and mild anxiety, 60 tablets

60 tablets

£ 13.99

find your local stockist

For low mood and anxiety. Made from freshly harvested herbs.
More info

What's being asked

What is the difference between low mood and depression?

Typical symptoms of low mood include: - Low self esteem - Worrying - Tiredness - ...
Read more >

I am stressed. Will it be like this for the rest of my life now?

Stress has many causes and how long it tends to last depends on what's causing it and how we deal ...
Read more >

What are the causes of a panic attack?

A panic attack is generally triggered by heightened anxiety, usually through an anxiety provoking ...
Read more >

Are you stressed?

Take our simple 10 question test to see if you are under stress

Take the test

Here's what I recommend

As the A. Vogel Mood advisor, I recommend Stress Relief Daytime Drops to help relieve symptoms of stress and anxiety.

Learn more

Did you know?

When we feel stressed or anxious our body responds as though we are under attack, releasing a surge of adrenaline which can cause a number of baffling bodily behaviours including palpitations, shortness of breath and even a dry mouth!

The physical symptoms our emotions cause

Healthy & nutritious dinner ideas

Get new recipes in your inbox every week. Sign up now