Can Dehydration Cause Anxiety?

Jill Johnson

Reviewed by Jill Johnson

Written by Nicholas Gibson

Updated 02/07/2023

Can dehydration cause anxiety? Here’s everything you need to know.

Anxiety is a common feeling we all develop from time to time, especially when stress from family life, money problems or other issues accumulates.

For some people, anxiety isn’t just an occasional issue. In fact, an estimated 31 percent of all U.S. adults are affected at some point in life by clinical anxiety disorders involving ongoing or severe anxiety symptoms that get in the way of daily activities.

Experts have identified a number of factors that can contribute to feelings of anxiety — and falling behind on your fluid intake appears to be one of them.

So, can dehydration cause anxiety? Although becoming dehydrated doesn’t appear to be a cause of anxiety disorders, failing to drink enough might make you feel more anxious or cause your existing anxiety symptoms to become worse.

Below, we’ll talk about the link between dehydration and anxiety and share a few common warning signs to look for if you’re concerned you may not be drinking enough.

We’ll also list some simple ways to stay hydrated, as well as options for managing anxiety symptoms and improving your mental well-being.

Anxiety is a normal emotion that involves feelings of tension, worry and physical changes, such as trembling, a rapid heartbeat or elevated blood pressure.

Everyone feels anxious from time to time. However, if you have an anxiety disorder, you might be prone to feeling anxious in situations that shouldn’t cause you to worry or have panic symptoms that occur in certain settings. 

Our guide to normal anxiety compared to anxiety disorders goes into more detail about the main differences between regular feelings of anxiety and mental health disorders, such as generalized anxiety disorder (GAD).

Researchers aren’t yet aware of exactly what causes anxiety disorders to develop. However, current scientific evidence suggests that a mix of genetic and environmental factors, including a person’s exposure to stressful or negative life events in childhood, may play a role.

Dehydration is a condition that can occur when your body loses an excessive amount of fluids, such as by failing to drink enough water throughout the day. 

It’s common to become dehydrated if you have an illness that causes vomiting and/or diarrhea, if you live in a hot climate that causes you to sweat often, if you have a fever or if you currently use medication that increases your need to urinate.

Dehydration can have a serious negative impact on your physical and mental health, including by increasing your risk of depression and anxiety.

In a randomized controlled trial published in the British Journal of Nutrition in 2011, researchers assessed the effects of mild dehydration on the mood and brain function of 26 men in their late teens and early 20s.

They found that even a small level of dehydration produced an increase in fatigue, anxiety and tension at rest. They also found that the participants were more likely to make errors in certain cognitive tasks when they were dehydrated. In other words, feeling dehydrated increased the participants’ risk of anxiety, all while having a negative effect on their general mental performance.

A different study conducted on women in their 20s also found that dehydration had a clear effect on mood and cognition, including disturbances in mood, headaches and reduced energy levels.

From a scientific perspective, these results are entirely predictable. After all, around 80 percent of your brain is made up of water, divided between different areas.

Dehydration can have a negative effect on your heart, kidneys and other internal organs that rely on a consistent supply of water for optimal function. So it shouldn’t come as a surprise that being dehydrated can affect your brain and potentially contribute to higher levels of anxiety. 

One way dehydration may affect your brain is by reducing blood flow. Since water makes up a significant amount of your blood volume, becoming dehydrated may affect the flow of blood to your brain.

In fact, research has found that being dehydrated can reduce cerebral blood flow — blood supply to the brain — during exercise.

It’s not yet clear if this reduction in blood flow occurs in everyone who becomes dehydrated or if it’s closely related to anxiety. However, it’s an interesting finding suggesting that the effects of dehydration on your brain function and moods may be both direct and indirect.

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Dehydration can develop surprisingly quickly, especially if you’re sick, engage in lots of physical activity or have a medical condition that increases your need to drink plenty of water throughout the day.

Common warning signs of dehydration in adults include:

  • Dry skin, a dry mouth and/or dry lips

  • Feeling tired without any clear reason

  • Dark yellow or orange-colored urine

  • Dizziness and/or disorientation

  • Sweating less than normal

  • Feeling excessively thirsty

  • Rarely urinating  

Because fluids account for a large amount of your body mass, you might notice that you weigh slightly less when dehydrated than when you maintain a healthy water intake.

It’s important to increase your water levels when you notice these warning signs, as even mild dehydration can become severe quite quickly in certain situations. 

More severe symptoms of dehydration include feelings of confusion, an inability to pass urine, an increased heart rate, rapid breathing, fainting and shock. 

It’s important to get medical help right away if you notice any of these symptoms or if you feel like it’s impossible to maintain a normal level of water consumption.

Dehydration can creep up on you as a result of a higher temperature, an illness or just a slight decrease in the amount of water you drink on a daily basis.

The good news is that it’s usually easy to avoid becoming dehydrated by making a few simple changes to your daily habits. Try the following to reduce your risk of dehydration:

  • Make drinking water a habit. The easiest way to avoid becoming dehydrated is to get plenty of fluids, especially water. While there’s no one-size-fits-all water intake for every person, eight to 10 glasses of water per day is generally a good target. To make drinking water easier, try to have a glass of water with every meal, as well as a few ounces of water whenever you start to feel thirsty.

  • Carry a water bottle with you. If you often avoid drinking water because you’re out of the house or at work, try carrying a water bottle with you. If your workplace has a water cooler, fill it up every few hours to maintain a steady plain water intake while you work.

  • Increase your water intake when it’s hot or humid. Hot weather can easily make you sweat more than normal, leading to dehydration. Be sure to increase your plain water consumption when it’s hot, especially if you notice yourself sweating frequently.

  • Limit your intake of caffeinated or sugary beverages. Caffeinated drinks like coffee can have a mild diuretic effect, meaning they might cause you to urinate slightly more than normal shortly after consumption. If you drink coffee or energy drinks and often feel dehydrated, try to limit your intake to one or two servings each day. If you like sweet drinks, try sports drinks and other beverages that have a high water content relative to their amount of caffeine.

  • If you’re prescribed medication, check for effects on urination. Some medications might make you urinate more than normal, which could cause you to easily become dehydrated. If you’re prescribed medication and often notice symptoms of dehydration, talk to your healthcare provider.

  • If you drink alcohol, get plenty of fluids too. Alcohol is a mild diuretic, meaning you might become dehydrated when you drink beer, wine or spirits. Try to limit your alcohol intake and increase your water intake whenever you’re at the bar or club.

If you occasionally feel anxious or worried when dehydrated, making simple changes to your habits, such as drinking more water throughout the day, may reduce the effects of dehydration and help you to stay calmer during times of stress.

However, if you often feel anxious even when you aren’t dehydrated, you might consider talking to a mental health professional.

Anxiety disorders are common, and receiving treatment can help you to gain more control over your symptoms, change the way you feel and improve your quality of life.

We offer treatment for anxiety online via our psychiatry services, allowing you to connect with a provider and, if appropriate, access medication to control anxiety.

In addition to using medication, other options for treating anxiety include taking part in therapy, using stress management techniques such as mindfulness, eating a balanced diet and letting your close friends and family members know how you feel.

We provide online therapy and anonymous support groups as part of our wide range of mental health services, allowing you to get support and professional help from the privacy and comfort of your home.

You can also learn more about healthy habits for managing anxiety symptoms with our guide to calming anxiety.

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Dehydration can affect every part of your body, including your brain. Several studies, including randomized controlled trials, show a link between dehydration and anxiety, indicating that your risk of feeling anxious might increase if you’re not drinking enough water.

If you often feel anxious and also have other common symptoms of dehydration, boosting your water consumption may help reduce the severity of your symptoms. 

In addition to potentially helping you feel better, staying hydrated is important for your overall physical health and well-being. 

If you think you may have an anxiety disorder, consider talking to a mental health expert about possible treatment options. You can access help online by taking part in a mental health consultation through our telehealth platform. 

You can also learn more about your options for successfully managing anxiety with our full guide to anxiety disorder treatments, which covers everything from natural options to medication.

10 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. Any Anxiety Disorder. (n.d.). Retrieved from
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  5. Ganio, M.S., et al. (2011, November). Mild dehydration impairs cognitive performance and mood of men. The British Journal of Nutrition. 106 (10), 1535-1543. Retrieved from
  6. Armstrong, L.E., et al. (2012, February). Mild Dehydration Affects Mood in Healthy Young Women. The Journal of Nutrition. 142 (2), 382-388. Retrieved from
  7. Haghighatdoost, F., et al. (2018, September). Drinking plain water is associated with decreased risk of depression and anxiety in adults: Results from a large cross-sectional study. World Journal of Psychiatry. 8 (3), 88-96. Retrieved from
  8. Oros-Peusquens, A.M., et al. (2019). A Single-Scan, Rapid Whole-Brain Protocol for Quantitative Water Content Mapping With Neurobiological Implications. Frontiers in Neurology. 10, 1333. Retrieved from
  9. Trangmar, S.J., et al. (2015, November). Dehydration accelerates reductions in cerebral blood flow during prolonged exercise in the heat without compromising brain metabolism. Heart and Circulatory Physiology. 309 (9), H1598-H1607. Retrieved from
  10. Zhang, Y., et al. (2015, September). Caffeine and diuresis during rest and exercise: A meta-analysis. Journal of Science and Medicine in Sport. 18 (5), 569-574. Retrieved from

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Jill Johnson

Dr. Jill Johnson is a board-certified Family Nurse Practitioner and board-certified in Aesthetic Medicine. She has clinical and leadership experience in emergency services, Family Practice, and Aesthetics.

Jill graduated with honors from Frontier Nursing University School of Midwifery and Family Practice, where she received a Master of Science in Nursing with a specialty in Family Nursing. She completed her doctoral degree at Case Western Reserve University

She is a member of Sigma Theta Tau Honor Society, the American Academy of Nurse Practitioners, the Emergency Nurses Association, and the Air & Surface Transport Nurses Association.

Jill is a national speaker on various topics involving critical care, emergency and air medical topics. She has authored and reviewed for numerous publications. You can find Jill on Linkedin for more information.

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