The only way to treat dehydration is to rehydrate the body with rehydration fluids, available from pharmacies.
If your baby is dehydrated, take them to see your GP as soon as possible. They'll be able to recommend an oral rehydration solution, described below.
Giving your baby regular sips (a few times an hour) of oral rehydration solution in addition to their usual feed (breastmilk, formula milk and water) will help to replace lost fluids, salts and sugars.
Avoid giving your baby fruit juice, particularly if they have diarrhoea and vomiting, because it can make it worse.
Infants and children
Infants and children who are dehydrated should also take an oral rehydration solution.
If your child is finding it difficult to hold down fluids because of vomiting, give them smaller amounts more frequently. You may find it easier to use a spoon or a syringe.
Read more about vomiting in adults and vomiting in children and babies.
Oral rehydration solutions
When you're dehydrated, you lose sugar and salts, as well as water. Drinking a rehydration solution will enable you to re-establish the right balance of body fluids. The solution should contain a mixture of potassium and sodium salts, as well as glucose or starch.
There are several different rehydration products available over the counter from pharmacies or on prescription from your GP, including solutions that are suitable for infants and children.
Ask your GP or pharmacist for advice about the most suitable rehydration solution for you or your child.
Seek immediate medical help if you suspect someone is severely dehydrated (see symptoms of severe dehydration).
They may need to be admitted to hospital for treatment. In particular, babies, infants and elderly people will need urgent treatment if they become dehydrated.
Fluid may be given up the nose using a nasogastric tube or using a saline drip into a vein (intravenously). This will provide essential nutrients faster than using solutions that you drink.
If you have had bowel surgery, some rehydration solutions may not contain enough salt. In this instance, you will need a higher-strength solution. Your GP or surgeon can recommend a suitable rehydration solution for you.