Top of the pageCheck Your Symptoms

Dehydration

Overview

Dehydration occurs when your body loses too much fluid. This can happen when you stop drinking water or lose large amounts of fluid through diarrhea, vomiting, sweating, or exercise. Not drinking enough fluids can cause muscle cramps. You may feel faint. Usually your body can reabsorb fluid from your blood and other body tissues. But by the time you become severely dehydrated, Opens dialog, you no longer have enough fluid in your body to get blood to your organs. You may go into shock, Opens dialog, which is a life-threatening condition.

Dehydration can occur in anyone of any age. But it's most dangerous for babies, small children, and older adults.

Dehydration in babies and small children

Babies and small children have a greater chance of becoming dehydrated, Opens dialog. That's because:

  • A greater portion of their bodies is made of water.
  • Children have a high metabolic rate, Opens dialog, so their bodies use more water.
  • A child's kidneys don't conserve water as well as an adult's kidneys.
  • A child's natural defense system that helps fight infection (immune system, Opens dialog) isn't fully developed. This makes them more likely to get an illness that causes vomiting and diarrhea.
  • Children often won't drink or eat when they aren't feeling well.
  • They depend on their caregivers to provide them with food and fluids.

Dehydration in older adults

Older adults have a greater chance of becoming dehydrated because they may:

  • Not drink because they don't feel thirsty.
  • Have kidneys that don't work well.
  • Choose not to drink because they can't control their bladders (incontinence, Opens dialog).
  • Have physical problems or a disease that makes it:
    • Hard to drink or hold a glass.
    • Painful to get up from a chair.
    • Painful or exhausting to go to the bathroom.
    • Hard to talk or communicate to someone about their symptoms.
  • Take medicines, such as antihistamines or blood pressure medicines, that increase urine output.
  • Find it harder to eat a healthy diet.

Early symptoms of dehydration

Watch babies, small children, and older adults closely for the early symptoms of dehydration anytime they have an illness that causes high fever, vomiting, or diarrhea. These are the early symptoms of dehydration:

  • The mouth and eyes may be drier than usual.
  • The person may pass less urine than usual.
  • The person may feel cranky, tired, or dizzy.

Related Videos

Information about Dehydration

Current as of: July 31, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.