Dehydration: A Complication That May Arise From Diarrhea
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Dehydration: A Complication That May Arise From Diarrhea

Dehydration: A Complication That May Arise From Diarrhea
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Updated on March 3, 2024
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Diarrhea is a common ailment that plagues everyone from time to time. It can be caused by a bacterial, viral, or parasitic infection or may be a side effect of a medication. Diarrhea may also be caused by certain foods or can be a sign of a more serious health problem, such as a digestive disorder.

Typically, diarrhea clears up on its own within a few days and is not a cause for concern.

 But severe or frequent diarrhea can be a sign of a bigger health issue that needs medical attention. If left untreated, diarrhea can lead to dehydration, which comes with its own health concerns.

Signs of Dehydration From Diarrhea

The biggest and most clinically important complication of diarrhea is dehydration, which occurs when you lose more fluid than you take in. When this happens, your body doesn’t have enough water or, frequently, electrolytes to carry out its normal functions.

Anyone can get dehydrated, but it is more common and more dangerous in young children, elderly people, and those with weakened immune systems.

Signs of dehydration include:

  • Excessive thirst
  • Less frequent urination
  • Dark-colored urine
  • Dry mouth and tongue
  • Dry skin
  • Tiredness
  • Sunken eyes or cheeks
  • Light-headedness or fainting
  • Decreased skin turgor (when the skin is pinched and released, it does not return to normal right away)

These signs should also alert parents to possible dehydration in children, with additional signs including a lack of energy, no wet diapers for three hours, listlessness or irritability, and the absence of tears while crying.

Dehydration can be mild, moderate, or severe. Complications include low electrolyte levels, seizures, urinary tract infections, kidney stones, and even kidney failure. Dehydration increases the risk of heat exhaustion and heatstroke in hot weather.

 In the most serious cases, dehydration puts stress on the heart and lungs and may lead to shock, which can be life-threatening.

Treating Dehydration

If you’re suffering from dehydration, drink plenty of water. You may also want to try sucking on ice cubes. But water may not be enough, as it does not contain the salts and electrolytes (minerals such as sodium and potassium) your body also needs to recover.

Drinking fruit juices and sports drinks, as well as eating soups with clear broths, can help replenish electrolyte levels.

 Just pay attention to the amount of sugar and artificial sweeteners in these drinks, as both can worsen diarrhea symptoms. Sports drinks may also be low in sodium. For these reasons, it is often more helpful for adults to use oral rehydration solutions such as Pedialyte.

For children, talk to your pediatrician about oral rehydration solutions as a way to treat diarrhea and prevent dehydration.

If your dehydration from diarrhea is severe, your doctor may treat it with fluid via intravenous therapy (IV).

If treated quickly and appropriately, someone suffering from dehydration should recover completely.

Ways to Prevent Dehydration

You can prevent dehydration from occurring in the first place! It’s important to drink plenty of fluids every day, even when you are not sick. In warm and hot weather or when you are exercising, be sure to drink even more.


How much fluid you need depends on your age, weight, level of activity, and the climate where you live. Generally, it’s recommended that women drink eight glasses of water a day (about 2.2 liters) and men drink 12 glasses (about 3 liters) per day. However, you may be getting much of that already in drinks or foods with high water content, such as teas or soups, so talk to your doctor about the amount that is appropriate for you. Clear urine is a clear sign you’re drinking enough fluids.

Anyone who is sick with a fever, vomiting, or diarrhea should drink plenty of fluids and not wait for signs of dehydration to emerge.

If a loved one is ill, pay close attention to how much they drink, especially children and older adults. Even minor illnesses, such as influenza, bronchitis, and bladder infections can lead to dehydration in older adults, so it’s important to watch out for the signs.If you think someone in your family may become dehydrated, call your doctor before they begin to show signs of dehydration.

When to Seek Medical Help

While most people who are dehydrated will recover completely, there are instances where medical attention is necessary to prevent further complications.

Call 911 immediately if:

  • The person loses consciousness at any time
  • There is any other change in the person's alertness, such as confusion or seizures
  • The person has a fever over 103 degrees F
  • You notice symptoms of heatstroke, including rapid pulse or rapid breathing
  • The person’s condition does not improve, or gets worse despite treatment

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Natalia Johnsen, MD

Medical Reviewer
Member of American College of Lifestyle Medicine

Natalia Johnsen, MD, is a triple board-certified physician in internal medicine, lifestyle medicine, and obesity medicine, practicing as an internist and consultant at the Vancouver Clinic in Vancouver, Washington.

Dr. Johnsen began her medical career as an ob-gyn in Russia before relocating to the United States in 2000. She completed her internal medicine internship at the University of Nevada and her residency at a Stanford-affiliated program in Santa Clara, California.

Deeply interested in the impact of lifestyle on both physical and mental health, Johnsen transitioned her focus toward prevention-based care after witnessing how many chronic conditions could be avoided or improved through lifestyle interventions. She became board-certified in lifestyle medicine in 2021 and further expanded her expertise by earning board certification in obesity medicine in 2025.

Johnsen is passionate about empowering patients with evidence-based tools to achieve sustainable health and long-term well-being.

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Ashley Welch

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Ashley Welch has more than a decade of experience in both breaking news and long-form storytelling. She is passionate about getting to the crux of the latest scientific studies and sharing important information in an easy-to-digest way to better inform decision-making. She has written about health, science, and wellness for a variety of outlets, including Scientific American Mind, Healthline, New York Family, Oprah.com, and WebMD.

She served as the health editor for CBSNews.com for several years as a reporter, writer, and editor of daily health news articles and features. As a former staff member at Everyday Health, she covered a wide range of chronic conditions and diseases.

Welch holds a bachelor's degree from Fordham University and a master's degree from the Craig Newmark Graduate School of Journalism at the City University of New York, where she studied health and science reporting. She enjoys yoga and is an aspiring runner.

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Resources
  1. Diarrhea: Symptoms and Causes. Mayo Clinic. August 22, 2023.
  2. Symptoms and Causes of Diarrhea. National Institute of Diabetes and Digestive and Kidney Diseases. November 2016.
  3. Dehydration: Symptoms and Causes. Mayo Clinic. October 14, 2021.
  4. Dehydration. MedlinePlus. December 29, 2023.
  5. Diarrhea. Cleveland Clinic. September 20, 2023.
  6. Is Something in Your Diet Causing Diarrhea? Harvard Health Publishing. August 8, 2023.