5 Ways How Dehydration Affects Your Brain


I always keep a ‘drink water’ reminder for my self on my phone because, during the everyday hustle and bustle, I often forget to drink enough water. We all know that our body contains about 11 gallons of water meaning your blood contains 85% water, your muscles 80% of water, your brain 75% and your bones 25%. Hence water is really essential for the proper functioning of your body throughout the day.

But before my friend suggested the reminder, I used to dehydrate myself like a dry cactus! I drank water only while eating my lunch or dinner; never in between. It not only affected my body but my brain too. I wasn’t able to think clearly or concentrate on anything at the end of the day and I would just feel tired all the time. So as I write this article, sipping the almighty tall glass of water, I am going to reveal some of the shocking facts about how dehydration affects your brain. Let’s begin!


1. Dehydration diminishes your cognitive skills

Our brain completely depends upon water to function at its optimum level, hence lack of enough water results in the imbalance between the brain cells and they ultimately lose efficiency. Once your brain cells start to slow down, your cognitive skills also start to degrade. A study conducted at Loughborough University showed that participants who were dehydrated committed a significantly greater number of errors such as lane drifting and late braking in a two-hour driving experiment. It further showed that their performance was just as bad as those who completed the same simulation while intoxicated. This clearly shows that dehydration reduces your focus and cognitive skills.

2. Dehydration makes you forgetful

When your body is lacking enough water, it increases the strain in your brain as the efficiency of your brain degrades in every hour. It affects the sodium and electrolyte levels in the body which has been linked with memory and other cognitive changes.  It also impairs the metabolic activity of the brain, exerting a higher level of neuronal activity to maintain a normal performance. Experts and scientists have also concluded that “given the limited availability of brain metabolic resources, the findings of our research suggest that prolonged states of reduced water intake may adversely impact executive functions such as planning and memory.”


3. Dehydration makes you cranky

Prolonged dehydration can make you cranky and moody. Doctor Harris Lieberman, Ph.D., a scientist with U.S. Army who studied different types of effects of dehydration on the brains of women found that dehydrated women experienced a significant drop in energy and mood. They felt drowsy and cranky all the time, and they even reported their regular mood swings and difficulty in concentration. Lieberman has yet to study the exact reason why your brain flips out when it becomes dehydrated but he states that

The mood and energy changes may be some sort of built-in alarm system, there to let you know you need water.”


Hence, dehydration results in a measurable increase in ‘total mood disturbance.”

Also See: What Is Bipolar Disorder? | Bipolar Mood Disorder: Types, Causes, Signs And Symptoms, & Management

4. Dehydration slows down your brain

Our brain is composed of 75% oater. Hence, once you get dehydrated your brain will start to shrink in its volume. This results in dehydration-induced headaches,  fatigue, lack of focus in anything, all of which will slow down your brain. Any slight dehydration can instantly result in a homeostatic imbalance making you feel difficult to carry on basic things like memorizing things or make conclusions or drive carefully and so on. I am not saying that you need to drink like 11 gallons of water per day, just make sure you’re hydrated.

5. Dehydration causes insomnia

Dehydration before sleeping will definitely mess up your sleep cycle. Though you might not drink enough water before going to bed thinking it will make you get up in the middle of the night. Water increases the blood flow to your brain, making it oxygenated and hydrated. Once you fall asleep, you need a stable brain to keep you rested and calm during the sleep. Lack of enough water will induce headaches and anxiety which eventually messes up your sleep and cause insomnia.

This leaves us to another widely popular conundrum. 

How do you know you’re dehydrated?

Well, I am not a crazy sportsperson who has her own personal team of hydration experts but when I am dehydrated I would definitely know through some signs and symptoms. Excessive hunger — sugar cravings in particular — is another common sign your body needs more water. In fact, aside from thirst, hunger is one of the first telltale signs of dehydration. Here’s the list of common signs and symptoms that you should consider when you’re feeling dehydrated.

  • Poor concentration and brain fog
  • Headache
  • Fatigue and dizziness
  • Muscle pain
  • Dry or sticky mouth
  • Constipation
  • Dark urinated
  • Mood disorders
  • Anxiety and stress
  • Sugar cravings
  • Insomnia

Having a hangover?  Read our blog :Check Out These 5 Expert Ways To Prevent A Nasty Hang Over

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