The Surprising Reason You Get Brain Fog More in the Summer

Aug 22, 2023 2 Min Read
woman pouring water from faucet

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The Science Behind Brain Fog

Water is life.

Pure water is the world's first and foremost medicine. - Slovakian proverb

Water is indispensable to the operation of each brain cell. And sometimes, getting enough can be a challenge.

Your brain is 80% water, and it's important to maintain stability. Even a small "drop-off" has consequences.


A 2018 study[1] found a 2% loss in hydration causes a measurable loss in focus and cognition. Two percent isn't that much. We may not even feel thirsty. If dehydration hits 5%, your loss of focus and concentration hits 35%.

Another study[2] found even one percent produces deficits.

All this can lead to mid-day grumpiness.

Here's one thing you can do right now:

   Drink one cup of water with each meal.

In no time your brain links meal and water. It becomes a habit. Remember, brains get good at what they do. Neuroplasticity!

( And, of course, sip water often all day. It does add up.)

You may also like these articles:

How to Make Your Brain 41.66% Happier

This is Your Brain on Music

Are You Short-Changing Your Brain?

Laughter is Good For Your Brain

So, maintaining a good mood might just meaning adding water.

Water is the soul of the earth. - W.H. Auden

This article was first published on

This article is also available in Chinese.

To read more interesting facts about the brain by Terry Small, please click here is an advertisement free website. Your continuous support and trust in us allows us to curate, deliver and upkeep the maintenance of our website. When you support us, you allow millions to continue reading for free on our website. Will you give today? Click here to support us

Edited by: Kiran Tuljaram

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Tags: Wellness, Brain Bulletin


1. Wittbrodt M.T. Millard-Stafford, M. Dehydration Impairs Cognitive Performance: A Meta-Analysis. Medicine & Science in Sports & Exercise, Nov., 2018

2. Stachenfeld, N. et al.  Water Intake Reverses Dehydration Associated with Impaired Executive Function in Healthy Young Women, Physiology & Behavior, Mar., 2018

Terry Small is a brain expert who resides in Canada and believes that anyone can learn how to learn easier, better, and faster; and that learning to learn is the most important skill a person can acquire.

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