Mild Dehydration: Is It Causing Memory Loss, Depression, Anxiousness, or Focus Problems?

Mild Dehydration

If you notice that your mood is low or your anxiety level is high, or you’re struggling to focus mentally or having trouble with recall, or are just generally feeling irritable, it could be that you need to drink some water. Even mild dehydration can dampen your mood and more, causing you to feel more depressed, anxious, tense, irritable, or antagonistic. That’s in addition to zapping your energy, increasing pain levels, and compromising your ability to concentrate, according to recent research.


Even mild dehydration can dampen your mood and more, causing you to feel more depressed, anxious, tense, irritable, or antagonistic. Click To Tweet

After all, water plays a vital role in every function in your brain and body. Your body is made up of water—roughly 75% when you are born, and closer to 60 % as an adult—and your brain is roughly 80% water. Your body won’t last more than 3 days without water, but it can survive 2 to 3 months on water alone!

To protect your brain health and function, healthy hydration is essential. Here are the ways dehydration happens, what it does to your brain, and better yet—how you can ensure you stay well hydrated.


Water is critical to virtually every function in your body. It is needed to regulate your body temperature; cushion your joints and lubricate your eyes; aid in digestion; maintain your blood pressure; transport important molecules and nutrients; remove waste; protect your organs and tissue; maintain electrolyte (sodium) balance; and prevent constipation, to name the most important.

Specific to brain function, water plays a vital role in producing and balancing hormone levels; maintaining healthy protective fluid levels to protect your brain and spinal cord from injury; creating new neurons and maintaining overall cellular brain health; flushing out metabolic waste that occurs in the brain, and ensuring healthy blood flow to the brain bringing oxygen and vital nutrients. It’s no wonder we need to drink an adequate amount of water every day to maintain health!

Dehydration happens when you lose more water than you take in, and your body struggles to carry out its normal functions. Technically, a body water loss of 1-2%, is considered mild dehydration, and it is more common than you think.

Children and older adults get dehydrated more easily than most people. One study published in the Journal of the American Medical Association found that 17% to 28% of older adults in the United States experience dehydration. Even more concerning, Harvard researchers found that nearly 55% of children aged 6-19 are not properly hydrated in a study published in the American Journal of Public Health. More than half a million hospital visits a year have been documented primarily due to moderate and severe dehydration.


Hot, dry weather, high altitudes, and vigorous exercise are all common causes of mild dehydration for any age, as well as any kind of illness. The most common cause of dehydration in young kids is severe diarrhea and/or vomiting. Older adults naturally have less water in their bodies, and they tend to have conditions or take medications that increase the likelihood of dehydration. That means even a minor illness in an elderly person can cause dehydration.

Of course, what you consume can make you more dehydrated. Taking diuretics, consuming salty foods, and drinking beverages high in alcohol, caffeine, and sugar can contribute to water loss. Also, it just may be that you don’t drink enough water or hydrating foods (juicy fruits and vegetables).


Medical experts provide the following symptoms as telltale signs of mild dehydration:

These symptoms of mild dehydration are usually remedied by drinking more fluids. However, severe dehydration may require medical attention. Signs of more severe dehydration might include extreme thirst, lack of sweat or tearing, confusion, listlessness, low blood pressure, rapid heart rate, sunken eyes, shriveled skin, and rapid breathing.


In addition to the more general signs of dehydration, experts have noted compromised cognitive function resulting from even the slightest amount of dehydration. Indeed, one study examined the effects of mild dehydration of 2% on cognition and found impaired performance in tasks that require attention, short-term memory skills, and physical movement. Additional research on mild dehydration, this time with less than 1.5% water loss in healthy young women, found it was associated with compromised mood, increased perception of task difficulty, lowered concentration, and headaches.

Increased anxiety was also noted in a study on dehydration published in the British Journal of Nutrition. The researchers observed 20 healthy women go without fluids for 24 hours. The women experienced confusion, decreased alertness, and increased sleepiness during their period of dehydration. Interestingly, a similar study, but conducted on men, found slightly different results. It showed a decrease in vigilance and working memory and an increase in tension/anxiety and fatigue

What’s more, mild dehydration is associated with reduced brain volume, according to one experimental study.  Cognitive deficits related to dehydration may have real-life consequences too, another study found. It examined 40 randomly selected healthy pilots. The dehydrated pilot group showed significantly poorer flight performance and spatial cognition test scores.


Make hydration a priority to ensure optimal brain health by following these tips.

  • Drink plenty of water. Your daily water needs vary depending on your age, physical activity level, and the weather. As a general rule, drink 8-10 glasses of water a day (a glass being 8 ounces).
  • Consume fruits and vegetables. Remember, you can keep your brain well hydrated by consuming water-rich foods, such as juicy fruits and vegetables such as lettuce, celery, bok choy, radish, cucumber, zucchini, watercress, tomatoes, green bell peppers, and asparagus.
  • Limit what dehydrates you. Avoid drinking sugary beverages, highly caffeinated drinks (energy drinks), alcohol, fruit juice, sodas, and diet drinks as much as possible. Sugar, alcohol, and caffeine can make dehydration worse.
  • Hydrate when you sweat through exercise. Carry a reusable bottle filled with water with you.
  • Don’t wait to get thirsty to hydrate. Thirst is a sign you are already dehydrated.
  • Have fun with hydration! Enjoy plain sparkling water, spa water (water flavored with fruit like melon, strawberry, or citrus), water with flavored stevia, coconut water, herbal tea, and green and black tea (in small amounts, if caffeinated).


Help your brain and body to work optimally by staying properly hydrated, and they will work better in return. You’ll likely enjoy better psychological well-being and moods—and you may even get a better night’s sleep!

Anxiety, mood issues, cognitive problems, and other mental health issues can’t wait. At Amen Clinics, we’re here for you. We offer in-clinic brain scanning and appointments, as well as mental telehealth, clinical evaluations, and therapy for adults, teens, children, and couples. Find out more by speaking to a specialist today at 888-288-9834 or visit our contact page here.


  1. I had a really long and very stressfull 16 hour day at work recently, had a 12 oz coffee that morning, a large sugary Dansih a couple of hours later and only drank a half liter (1 pint) of water that whole day. Ate a nreakfast croissant (turkey saisage, egg, cheese) around 3 pm and around 9:30 pm I started sweating and feeling nauseous. I them fainted after getting up to use the bathroom as I thought I might need to vomit. I ended up being taken to the ER. After a battery of tests including CT scans, X-Rays, EKG, Ultrasound, covid and blood work, I was released with a diagnosis of Fatigue and drum roll…Dehydration : (

    Comment by Phil — December 12, 2022 @ 4:03 AM

  2. Have always struggled to drink 8-10 glasses of water a day. Sparkling water makes it a little easier. Good article!👍🏻

    Comment by Peter Tobia — December 12, 2022 @ 4:32 AM

  3. Everything is true that is printed in this article & timing is perfect that I read this reminder. I’m experiencing ALL of these symptoms so thank you & I can wait to see my symptoms improve!!!

    Comment by Karen Reiman — December 12, 2022 @ 6:32 AM

  4. I learned a lot from that article..Thank you!!

    Comment by Don Del Giorno — December 12, 2022 @ 12:01 PM

  5. I am desperately trying to get rid of Vertigo. I had a severe allergic reaction to car fresher at a local dealership, November 17. I have been sick since then. Went to Dr ,Chiropractor and my Massage therapist. I feel like I'm poisoned . I'm drinking water, maybe not enough. I am cleansing my nasal passages with saline. I am desperate for help!

    Comment by Sue Engle — December 12, 2022 @ 3:49 PM

  6. It concerns me that the media is reporting a new study that we don't actually need 8 glasses of water a day…. They keep pointing out that we get water from food, but the typical American is consuming what? Garbage that is dehydrating. However, even knowing that we need water couldn't make people drink water…. C'est la vie.

    Comment by Sadie — December 15, 2022 @ 10:31 AM

  7. Can you talk about mineralizing (mineral salt) your (filtered) water. Also the concept of energetic structured water. Thanks PS I had heard that distilled water is not good for the body.

    Comment by JC — December 20, 2022 @ 7:53 PM

  8. I found this article very interesting and wondered if there may even be a connection to vascular blood flow issues as it seems that the brain will selectively shut down less essential functions in favour of preserving its more important function. So it is wondered if brain functions are effected as the article notes clearly then what other, less critical, but essential for good health, may be adversely diminished particularly if dehydration, mild or more severe, persists over a longer time frame?

    Comment by Cliff Dahms — January 9, 2023 @ 8:49 AM

  9. wonderful information!

    Comment by Doug Morris — October 21, 2023 @ 4:21 PM

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