Dehydration in babies: How to spot if your baby is dehydrated and how to treat it

Dehydration in babies and children can be very serious if left untreated and if there isn't an obvious explanation, such as diarrhoea, it can be a sign of serious infection.

As the weather heats up it’s important to make sure you know how to spot if your baby is dehydrated and when to seek medical intervention.

Obviously, it’s much easier to know if you need to drink some more water because you can communicate your thirst and resolve the issue on your own. But, as babies and small toddlers are unable to say what’s wrong with them, it’s important you know the signs to look out for.

Signs of dehydration in babies, toddlers and children:

Dr Tim Ubhi, a Royal College of Paediatrics and Child Health spokesperson and clinical director of the Children’s e-hospital, says: ‘Dry nappies are the biggest indication of dehydration in newborns’.

A poor urine output, dark coloured urine and tired or subdued behaviour are also good indicators that your baby needs to drink more. You baby might also show signs of jaundice as a symptom of dehydration according to Dr Ubhi.

As your baby gets older and becomes a toddler, their physiological reserve improves and they are better able to cope with dehydration. This means that the symptoms vary a little and there are more ways to spot dehydration.

Poor urine output and lethargy are once again strong indicators that your child is dehydrated but their skin turgor and moisture may also become affected. The mucus membranes in their eyes and mouth will also become dryer, but these are signs of significant dehydration and the condition should be spotted before this.

dehydration in babies

If your little one isn’t producing much urine it could be a sign they are dehydrated

Causes of dehydration in babies, toddlers and children:

Dr Ubhi says that if you struggle to establish breastfeeding early on, dehydration is likely to occur. If your baby is refusing formula milk too it could be something more serious.

Dr Ubhi stresses that if your baby is not feeding regularly you should get medical advice as it can be the result of a serious infection like sepsis or another underlying health issue. It doesn’t have to be a doctor, you could consult a midwife or health professional but if you have a concern, do get it checked out.

In toddlers and children Gastroenteritis, a very common condition that causes diarrhoea and vomiting, is most likely to be the cause of dehydration. Your toddler might be able to communicate how they are feeling a little better and it’s important to ensure they are drinking plenty of water every day.

If you are confident that your toddler or child’s dehydration could caused by an infection (say someone else in the household has been suffering from diarohhea) then you probably don’t need to panic. However, if it comes out of the blue or their water intake drops below 50 per cent of their regular intake, book an appointment with your GP or go to A&E if the child is seriously ill.

How to treat dehydration and when to consult a doctor:

Rehydrate, rehydrate, rehydrate! Dr Ubhi stresses that it might seem fairly straightforward but it really is the best tactic. If your baby or child is taking in less than 50 per cent of their normal fluids you should seek medical intervention.

With newborn babies doctors are likely to first try cup feeding, giving the baby expressed breast milk or formula milk from a tiny cup to encourage them to drink. If this proves fruitless they’ll feed via a nasogastric tube which runs through the nose, past the throat and into the stomach.

Toddlers and children will not tolerate a nasogastric tube and will try to pull it out! If they struggle to drink a little water often, usually 10ml every 10 minutes, then doctors will try rehydration solutions and diaroyes and  will opt for an intravenous tube.

How much water should your baby, toddler or child be drinking?

girl drinking water

Dr Ubhi reveals this simple calculation to get an estimate on how much water your baby, child or toddler needs. For the first 10kg of weight, so up to the child’s first year, they need 100ml per kg of weight over 24 hours.

The average weight of a baby born in the UK is 7lbs 8oz (approximately 3.4kg), this means they would need they would need at least 340ml water over 24 hours.

When the child reaches between 10kg and 20kg, the intake goes down and they only need around 50ml per kg per 24 hours.

This gradually increases and adults need round two to two and a half litres of water a day.

When it comes to dehydration in babies, toddlers and children prevention is the best protocol. Encourage your little one to drink little and often especially during hot weather. Treats like squash, water melon and ice lollies will all help keep them hydrated but water is always the best option.