What is dehydration?

If your child loses a lot of body fluids or isn’t drinking enough, he might get dehydrated.

Gastroenteritis is the most common cause of dehydration. This is because it can make your child lose a lot of body fluids quickly. Any illness with persistent diarrhoeavomiting or reduced fluid intake can result in dehydration.

Lots of sweating can also result in dehydration, particularly in babies in very hot weather, or in adolescent children who are doing vigorous activity.

Symptoms of dehydration

A child who’s dehydrated might:

  • wee less often – a younger child might have fewer wet nappies or her nappies might not be as wet as usual
  • look gaunt and pale
  • be tired, lethargic or irritable
  • have fewer tears
  • be thirsty
  • have sunken and dark eyes
  • have a coated and dry tongue and mouth.

When to see a doctor about dehydration

You should see your GP if:

  • you’re worried that your child might be dehydrated
  • your child is vomiting often and can’t keep any fluids down
  • your child has lots of diarrhoea
  • your child is under the age of six months and has dehydration symptoms.

Take your child to a hospital emergency department straight away if:

  • your child has symptoms of severe dehydration – he’s not passing urine, is pale and thin, has sunken eyes, cold hands and feet, and is drowsy or cranky
  • your child has severe stomach pain
  • your child’s vomit is a green colour or has blood in it
  • you’re worried that your child is very unwell.

You know your child best, so trust your instincts if your child doesn’t seem well. Signs that your child has a serious illness that needs urgent medical attention include severe pain, drowsiness, pale or blue skin, dehydration, troubled breathing, seizures and reduced responsiveness.

Treatment for dehydration

You can treat mild cases of dehydration by giving your child more fluid.

One option is oral rehydration fluid like Gastrolyte®, Hydralyte™, Pedialyte® or Repalyte®. You can buy these fluids over the counter from a pharmacy.

Other options include water, diluted lemonade, cordial or fruit juice. If you’re using a sugary drink, it’s important to dilute it – use one part of lemonade, cordial or juice to four parts of water.

Your child might not be keen to drink. You can try to get her drinking more by giving her drinks via a syringe or spoon, or letting her suck icy poles. You can get Hydralyte™ icy poles from pharmacies.

If your child is vomiting, it’s usually better to offer small amounts, but frequently. For example, give your child a few mouthfuls every 15 minutes.

If you have a breastfed baby older than six months, keep breastfeeding but feed more often. You can give your child extra oral rehydration fluid between feeds.

If your baby is older than six months and is bottle fed, give him oral rehydration fluid for the first 24 hours only and then reintroduce full-strength formula in smaller, more frequent feeds. You can still offer extra oral rehydration fluids between feeds.

In more severe cases, your child might need to go to hospital to catch up on fluid loss.

In many cases, the safest and quickest way to do this is by via a small tube that goes into your child’s nose and then into his stomach. The rehydrating fluids go through this tube. Less often, your child will be given fluids intravenously (directly into the vein).

Prevention of dehydration

The best way to avoid significant dehydration is to see your doctor if your child has an illness that’s causing her to lose lots of fluid or stop drinking.

On hot days or when your child is exercising, he needs to stay hydrated. Make sure there’s plenty of water handy so your child can drink if he’s thirsty. You might need to remind some children to have regular drink breaks.