Dehydration risks for babies, children and teenagers

Your child might be at risk of dehydration if they aren’t drinking enough fluids or can’t drink enough fluids in the following situations:

• The weather is hot.
• Your child is doing physical activity and sweating a lot.
• Your child has diarrhoea, vomiting, fever or another illness.

Dehydration is a lack of water in your body. Signs of dehydration include fewer wees (with lighter or fewer wet nappies in babies), sunken eyes, dry tongue and mouth, loss of weight, tiredness and low energy.

Preventing dehydration in hot weather and during physical activity

In hot weather or when your child is exercising, make sure there’s plenty of fluids for your child to drink.

For children under 6 months, you can offer extra feeds of breastmilk or formula.

For children 6 months and older, you can offer more water.

You might need to remind some children to have regular drink breaks if they’re playing sport or being active in hot weather.

Preventing dehydration during illness

Your child might be at particular risk of dehydration if they can’t drink or keep enough fluids in their body because of symptoms like vomiting, diarrhoea or fever.

If your child is unwell and at risk of dehydration, the fluids your child needs and how often they need them depend on your child’s age.

Babies 0-6 months

• If your baby is breastfed, offer extra breastfeeds or expressed breastmilk.
• If your baby is formula fed, offer the usual total amount of formula but in smaller, more frequent feeds.

Babies 6-12 months

• If your baby is breastfed, offer extra breastfeeds or expressed breastmilk.
• If your baby is formula fed, offer the usual total amount of formula but in smaller, more frequent feeds.
• Between feeds, offer water, oral rehydration solution or rehydration alternatives.

Children 12 months and older
Offer small amounts of water, oral rehydration solution or rehydration alternatives often – for example, a few mouthfuls every few minutes.

If your child doesn’t want to drink, try offering small amounts of fluids often via a syringe, spoon or straw. Or it might help to chill drinks first. You could also freeze fluids for your child to suck as icy poles.

Dehydration treatment

In mild cases of dehydration, your child might need more fluids than above. For example, babies aged 0-6 months might very occasionally need oral rehydration solution on top of extra feeds of breastmilk or formula.

Your GP can tell you how much fluid your child needs.

If your child is very dehydrated, very unwell or can’t keep enough oral fluids down, they might need get fluids through a tube that goes up their nose and into their stomach or directly into a vein through a drip. In this case, your child will have to go into hospital.

Oral rehydration fluids and alternatives

It’s best to use an oral rehydration solution like Gastrolyte, Hydralyte, Pedialyte or Repalyte.

You can buy these fluids over the counter from a pharmacy or supermarket. They might come as premade liquid, powder or icy poles for freezing. It’s important to make up the liquid carefully according to the instructions on the packet.

If you can’t get oral rehydration solution, you can use diluted lemonade, cordial or apple juice. Use 1 part of lemonade, cordial or apple juice to 4 parts of water.

Acidic fruit juices like orange juice and any full-strength lemonade, cordial or fruit juice might make diarrhoea worse, so don’t give these to your child.