Dehydration in children and babies

Dehydration is when your body gets too dry. In tamariki it is often caused by not eating or drinking when they are unwell, or having a fever, vomiting (being sick) or diarrhoea (runny poos).

On this page, you can find the following information:

What is dehydration?

Dehydration is when your body gets too dry. Your body can get dehydrated from losing water and salts. In tamariki it is often caused by not eating or drinking when they are unwell, or having a fever, vomiting (being sick) or diarrhoea (runny poos). It can also happen when they are outside in very hot conditions. Young children and babies are more likely to become dehydrated than adults. Keeping your child hydrated is always important, but it is especially important when they are unwell.

Mild dehydration in healthy children usually isn't dangerous. But more severe dehydration can cause the body to shut down and can even become life-threatening.

What are the signs of dehydration?

If your child is mildly dehydrated, they may have:

  • dizziness or light-headedness
  • nausea (feeling sick) or headaches
  • dark yellow or brown urine (wee) – urine should be pale yellow
  • fewer wet nappies or nappies not as wet as usual; or older children will not go to the toilet as much
  • dry lips, tongue, mouth or throat.

If you have a child under the age of 6 months who is vomiting (being sick) or has diarrhoea (runny poos), or you think they might be dehydrated, take them to a doctor right away. 

If your child of any age has the following signs of severe dehydration, call your GP immediately or go to your closest hospital emergency department.

Signs of severe dehydration

  • Dry mouth, lips and tongue.
  • Fewer wet nappies than usual or dark-coloured urine (pee).
  • No tears when crying or sunken eyes.
  • Cold hands and feet.
  • Mottled bluish skin.
  • Unusual lack of energy, sleepiness or difficult to wake.

How do I prevent dehydration in babies and children?


Carry on breastfeeding, or bottle feeding your pēpi/baby. You may need to feed them more often and drink extra liquid yourself if you are breastfeeding. Don’t dilute baby formula, use it as usual. If your child is over 1 year old, and you are giving them cow’s milk, continue to do so.

Toddlers and older children

Keep giving your child drinks even if they say they’re not thirsty, or if they vomit. They need to stay hydrated so they can get well. Water is the best thing for your tamariki/child to drink but if they are not already dehydrated, you can give them the following drinks.

Note that you do need to dilute the following drinks by adding water. They contain too much sugar which can make dehydration worse.

Type of drink How to dilute
Apple juice Mix 1 part juice to 1 part water.
Cordial Make up as normal then mix 1 part cordial to 1 part water.
Fizzy drinks such as lemonade  Mix 1 part fizzy to 1 part warm water (warm water removes the bubbles).

Should I give my child oral rehydration solutions?

If your child is having a lot of runny poos or is being sick a lot, your healthcare provider may recommend electrolyte solutions or oral rehydration solutions such as Gastrolyte, Electral or Pedialyte. You can buy these from your pharmacist and they are available on prescription – follow the instructions on the packet. Read more about oral rehydration solutions.

What drinks should I avoid giving my child?

Do not give infants or children undiluted soft drinks, fruit juices, Lucozade, Ribena, sports drinks (such as Powerade or Gatorade) - these contain too much sugar and can make your child's diarrhoea worse.

Avoid coffee and tea because these can make your child dehydrated.

How much liquid should I give my child?

Give your child small amounts of liquid often. Don’t give your child a lot to drink at one time. Give a 1/4 cup (50 mLs) every 15 minutes, or 1 teaspoon or 5 mLs in a syringe every minute is good.

  • Children aged 1–3 years need about 4 cups of liquid each day, including water or milk. A cup is 200-250 mLs. 
  • This amount increases to about 5 cups for 4–8-year-olds, and 7–8 cups for older children.

What foods can I give my child if they are unwell?

It is important to keep offering your child food as well as drinks when they are unwell. Your child may not want to eat when they are unwell. That doesn’t matter if they are drinking enough. Do offer them food, even if they have runny poos.

Starchy, simple foods are best – try bread or toast, porridge, rice, potatoes, plain biscuits, yoghurt or milk pudding.

Don’t give them fatty or sugary foods like takeaways, chippies, sweets, cakes, chocolate, ice cream, cream or coconut cream. These are hard to digest and can cause a tummy/puku upset.

Learn more

Gastroenteritis in children KidsHealth, NZ

Credits: Health Navigator Editorial Team. Reviewed By: Dr Alice Miller, FRNZCGP Last reviewed: 15 Feb 2022