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What is dehydration? — Dehydration is the term doctors use when the body loses too much water. Losing too much water is a problem, because the body needs a certain amount of water to work normally. Another word doctors sometimes use is "hypovolemia."
Dehydration can be mild or severe. Mild dehydration doesn't usually cause problems. But if mild dehydration isn't treated, it can get worse. Severe dehydration is a medical emergency and can be life-threatening.
Children are at higher risk for dehydration than adults. There are a few reasons for this:
Their bodies are smaller
They are more likely to get viruses that cause vomiting and diarrhea, which can lead to dehydration.
Babies and young children depend on adults to give them liquids, and might not be able to tell someone if they are thirsty.
What causes dehydration? — Dehydration happens when your body loses more water than you take in from drinking and eating.
It's normal for people to lose some water from their bodies every day, for example, in their urine and bowel movements. But some things make people lose a lot of water. In children, this can include:
A high fever
Problems or medicines that cause a person to urinate more than usual
Some things keep people from taking in enough water. For example, children might not drink or eat if they have an upset stomach or sore throat.
What are the symptoms of dehydration? — People with mild dehydration might not notice any symptoms.
As dehydration gets worse, it can cause symptoms such as:
Feeling thirsty
Urinating less often, or having dark yellow or brown urine
A dry mouth or cracked lips
No tears when the child cries
Feeling tired or confused
Feeling dizzy or light-headed
Eyes that look sunken in the face
A "sunken fontanel" in babies – A fontanel is a gap between the bones in a baby's skull. When babies are dehydrated, the fontanel on the top of their head can look or feel caved in.
Severe dehydration can make people stop breathing normally or go into a coma.
Should I call a doctor or nurse? — Call the doctor or nurse if your child has any symptoms of dehydration.
You should also call if your child:
Has diarrhea that lasts more than a few days
Has vomiting that lasts more than 1 day
Can't keep any fluids down
Vomits blood or has bloody diarrhea
Hasn't had anything to drink in many hours
Hasn't needed to urinate in the past 6 to 8 hours (in older children), or hasn't had a wet diaper for 4 to 6 hours (in babies and younger children)
Is there a test for dehydration? — Yes. Doctors can do blood and urine tests to check for dehydration and see how severe it is. Your child's doctor might also do tests to look for the cause of the dehydration.
How is dehydration treated? — Dehydration is treated with fluids.
Children with severe dehydration usually need to be treated in the hospital. Treatment might involve getting fluids through a thin tube that goes into the vein, called an "IV," or getting small sips of a special drink designed for children with dehydration.
If your child only has mild dehydration, you can also treat it by giving them fluids to drink. You'll know that the treatment is working when:
Your child urinates more often and the urine looks pale yellow or clear.
Your baby has more wet diapers.
Some fluids help treat dehydration better than water, because they give the body the right amount of water and salts. You should use the following fluids to treat your child's dehydration:
Oral rehydration solutions – These are special drinks meant to help with dehydration, such as Pedialyte. You can buy them in a store or pharmacy. Try to give your child a few teaspoons of fluid every few minutes. If your baby won't drink it from a bottle or cup, you can feed him or her with a spoon or syringe.
Breast milk – Babies who breastfeed should continue to breastfeed.
Apple juice mixed with an equal amount of water
The child can return to their normal diet once they are no longer dehydrated. Keep giving extra fluids if your child's vomiting or diarrhea continues.
Can dehydration be prevented? — Yes. To help prevent dehydration, you can:
Make sure your child drinks plenty of fluids, especially if he or she is sick and has a fever.
Give your baby or young child an oral rehydration solution as soon as he or she starts vomiting or having diarrhea.
Give your child extra fluids when it's hot out, or if he or she is exercising.
All topics are updated as new evidence becomes available and our peer review process is complete.
This topic retrieved from UpToDate on: Mar 30, 2020.
Topic 16940 Version 6.0
Release: 28.2.2 - C28.105
© 2020 UpToDate, Inc. and/or its affiliates. All rights reserved.

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