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Dehydration in babies and children - Dehydration

Babies and children are more at risk of dehydration than adults. Make sure that your child drinks enough fluids, such as milk or water, every day. This is especially important if your child is under 5 years old or is sick.

Dehydration in young children is common. It can be serious if it's not dealt with quickly. 

Non-urgent advice: Phone your GP if

you think your child is dehydrated and they:

  • are under 6 months old
  • have a chronic medical condition
  • are not improving after they are given more fluids
  • start showing signs that they need urgent medical help

Urgent advice: Take your baby or child to your GP or emergency department (ED) urgently if they:

  • seem drowsy (hard to wake)
  • are breathing fast
  • have few or no tears when they cry
  • have a soft spot on their head that sinks inwards (sunken fontanelle)
  • have a dry mouth
  • have dark yellow pee or have not had a pee in last 12 hours
  • have cold and blotchy-looking hands and feet
  • are extremely thirsty
  • are pale
  • have less energy than usual
  • have less than 3 wet nappies per day
  • seem confused

Symptoms of dehydration in babies and children

Symptoms of dehydration in babies and children are similar to symptoms of dehydration in adults

Thirst is one of the earliest signs. If your child is thirsty, give them a drink.

Other signs to also look out for in children and babies are:

  • complaints of a headache
  • fewer wet nappies than usual or their wet nappies may not feel as heavy (or be as wet) as usual

Dehydration can happen more easily in babies and children if they:

  • have a high temperature of 38 degrees Celsius or more
  • are not drinking enough fluids
  • have a chest infection - this can make it hard for babies and small children to drink or feed
  • are unwell with vomiting or diarrhoea
  • have sweated too much from playing sport or exercising
  • are too hot and losing fluids by sweating, for example, if they are wrapped in too many blankets
  • are out in very hot weather - read more about sun safety for babies and children

Reduce the risk of dehydration in children

Make sure that your child drinks enough fluids every day. This is especially important if your child is under 5 years old or is sick.

The amount of fluid your child needs depends on how old they are, how active they are and how hot the weather is. But most children aged 1 to 4 years old need 6 to 8 drinks a day.

Read advice on drinks for children aged 1 to 4 years


As a very rough guide, a baby should feed at least 8 to 12 times, or more, every 24 hours during the first few weeks of breastfeeding. Babies will breastfeed less often and sleep for longer as they get older.

If your baby is formula-fed, they should feed at least 6 to 8 times a day in the first 3 months, and then 4 to 6 times a day for the next 3 months. You can use a spoon to make it easier for your child to swallow the fluids.

Read more about how much formula your baby needs

Read advice on drinks to give your baby 0 to 12 months

Treating dehydration

If your child is over 6 months, you can usually care for them at home. If you are worried about them, get advice from your GP or pharmacist.


  • Carry on breastfeeding or using formula – try to give small amounts more often than usual.

  • Give babies on formula or solid foods small sips of water - use cooled boiled water if they are under 12 months.

  • Give small children their usual diet.

  • Give small children more fluid to drink.

  • Give regular small sips of rehydration solution to replace lost fluids, salts and sugars – ask your pharmacist to recommend one.


  • Do not make formula weaker by watering it down.

  • Do not give young children fruit juice or fizzy drinks even if they are gone flat – it makes things like diarrhoea or vomiting worse.

  • Do not give your child sports drinks - the caffeine in these drinks can be dangerous for children.

Once the dehydration has been treated, your child will need to keep drinking fluids regularly.

If your child has severe dehydration

Your GP will tell you if you baby or child is severely dehydrated.

Children with severe dehydration usually need to go to hospital for treatment. Sometimes, they'll be treated in the hospital's emergency department. But your child may need to be admitted into hospital overnight.

In hospital, a drip may be placed into your child's arm, hand or foot. A drip is a plastic tube that is placed into one of your child’s veins. Fluids can then be given directly into your child’s vein.

Sometimes, a feeding tube may be placed in your child’s stomach. This is usually passed through the nose. Milk feeds and fluids can be given through this tube.

Page last reviewed: 25 January 2021
Next review due: 25 January 2024

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 8.