In later stages of CKD, the kidneys are less able to filter blood and make urine. Some children start to urinate (wee) less often, or pass less urine (this is called oliguria). Occasionally, they cannot pass any urine (anuria).

After some time, this leads to a build-up of water and salts in the body – this is called fluid overload.

High blood pressure

When there is more water than usual in the blood vessels, this causes the blood pressure to rise – hypertension.

Swelling in the body

In some children, the fluid overload can cause swelling or puffiness in their body, especially around their eyes and in their legs and feet – this is called oedema.


Your child will have regular assessments for fluid overload. Your healthcare team may talk about target weight or dry weight. This is an estimate of what your child’s weight would be if he or she did not have fluid overload.

This allows the healthcare team to decide on any changes to the treatment.


Drinking fluids

Some children with CKD need to be on fluid restriction –they are given a limit to the amount of fluids (liquid) they can eat or drink each day. This may depend on what has caused CKD. Your child may need to:

  • drink less, such as water and juice
  • eat smaller amounts of food with a high amount of water (such as soups, porridge).

It can be difficult at first to know which foods have a high amount of water, and which your child can and cannot eat – but you will quickly learn. Your healthcare team – which may include a community nurse and/or a paediatric dietitian – will give you advice and help you design meals for your child. They may also provide measuring cups to help make sure your child gets the right amount to drink.

Your child may feel very thirsty at first – eating less salty food can help reduce thirst and helps control blood pressure.

This is different to advice for children who do not have CKD – who should drink plenty of water to avoid being dehydrated. There are also some types of CKD where the child needs to take MORE water than normal. Please make sure you understand how much fluid your child should take in. If you are unclear, please ask your doctor.


Your child’s doctor may prescribe medicine to control or reduce his or her blood pressure, in order to treat hypertension.

There are many types of medicines used to treat hypertension in children. Your doctor will prescribe the medicine that they think is best for your child.