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.

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

Babies and small children have an increased chance of becoming dehydrated because:

  • A greater portion of their bodies is made of water.
  • Children have a high metabolic rate, so their bodies use more water.
  • A child’s kidneys do not conserve water as well as an adult’s kidneys.
  • A child’s natural defence system that helps fight infection (immune system) is not fully developed, which increases the chance of getting an illness that causes vomiting and diarrhea.
  • Children often will not drink or eat when they are not feeling well.
  • They depend on their caregivers to provide them with food and fluids.

Older adults have an increased chance of becoming dehydrated because they may:

  • Not drink because they do not feel as thirsty as younger people.
  • Have kidneys that do not work well.
  • Choose not to drink because of the inability to control their bladders (incontinence).
  • Have physical problems or a disease which makes it:
    • Hard to drink or hold a glass.
    • Painful to get up from a chair.
    • Painful or exhausting to go to the bathroom.
    • Difficult to talk or communicate to someone about their symptoms.
  • Take medicines that increase urine output.
  • Not have enough money to adequately feed themselves.

Watch babies, small children, and older adults closely for the early symptoms of dehydration any time they have illnesses that cause high fever, vomiting, or diarrhea. The early symptoms of dehydration are:

  • A dry mouth and sticky saliva.
  • Reduced urine output with dark yellow urine.
  • Acting listless or easily irritated.
  • Muscle cramps.
  • Feeling faint.

Signs of severe dehydration include:

  • Sunken eyes, no tears, dry mouth and tongue.
  • Sunken soft spot on an infant’s head.
  • Little or no urine for 8 hours.
  • Skin that is doughy or doesn’t bounce back when pinched.
  • Shock.

Usually your body can reabsorb fluid from your blood and other body tissues. But by the time you become severely dehydrated, you no longer have enough fluid in your body to get blood to your organs. This may send you into shock, which is a life-threatening condition.

To prevent dehydration, drink 8 to 10 glasses of fluid (water and/or sports drinks) each day. Drink additional water before, during, and after exercise.

Treatment of mild dehydration involves stopping the fluid loss and gradually replacing lost fluids. Once the vomitting or diarrhea is under control, drink water a sip at a time until your stomach can handle larger amounts. If vomitting or diarrhea lasts longer than 24 hours, sip a rehydration drink such as Pedialyte or Gastrolyte to replace fluids and electrolytes in your body. They will prevent severe dehydration from occurring.

For severe dehydration, see your health professional immediately.