Symptoms in stages 1 to 3a 

In early stages of CKD, there are generally no symptoms. Most symptoms that are associated with  worsening kidney function start in later stages.

Your child may have symptoms associated with the underlying health condition that is causing the CKD. Many of these conditions are described in detail on the infoKID website.

Kidney conditions

Symptoms in stages 3b to 5

In later stages of CKD, many children start to develop symptoms. Your child’s healthcare team will speak with you about treatments to help these symptoms. 

Changes in urinating (weeing)

Some children with CKD are unable to make concentrated urine (wee). This means they pass a large amount of weak urine. They often need to drink lots of water to make up for the water they are losing in urine. 

Other children with CKD are unable to make much urine. This means they pass only a small amount of urine.

Fluid overload

If the kidneys are unable to make much urine, water and salts may build up in your child’s body – this is called fluid overload. This may cause swelling in his or her body (oedema). Medicines may be used to reduce the swelling.

High blood pressure

The kidneys become less able to control blood pressure, which may lead to high blood pressure (hypertension). Eating a no-added salt diet or taking medicines may help control blood pressure.

Poor nutrition and growth, and low energy

Children may develop a poor appetite, and not be able to eat as much. They may also feel sick (nausea) or be sick (vomit) because of the effects of CKD and/or the medicines they need to take. They may also feel more tired than usual and have low levels of energy.

Feeding devices may be used to help make sure children get all of the nutrients they need to grow.

Renal bone disease

The kidneys are less able to control the levels of calcium and phosphate and to activate vitamin D –these are all needed to keep bones healthy. Children may develop renal bone disease (renal osteodystrophy) – the bones become less strong, and may not grow normally. Some children have no symptoms, but some have pain in their bones or joints, and are at risk of bone fracture.

This is a very rare complication, and does not normally happen if your child follows medical and dietary advice.


Children may develop anaemia – a condition in which the blood has fewer red blood cells or less haemoglobin, a substance that is in red blood cells. Because red blood cells and haemoglobin carry oxygen around the body, children often feel weak and tired, and may look paler than usual.

Changes in amounts of electrolytes

Electrolytes are important chemicals in the body, which are also found in foods. We need the right balance of these to stay healthy. The kidneys help control the amounts of electrolytes. They include the following:

  • sodium – helps balance the amount of water in the body
  • potassium – is needed for the muscles, including the heart muscle, to work properly
  • bicarbonate – balances the amount of acid in our body, or the pH balance (also called the acid–base balance)
  • phosphate – helps keep bones, teeth and muscles healthy 
  • calcium – is important to keep bones and teeth healthy, helps blood to clot and also helps the muscles, including the heart muscle, to work properly.

Chronic kidney disease – stages 3b to 5 

Complications in stages 3b to 5

In later stages, children may be at risk of complications – other health problems associated with CKD. Although these are very rare, it is important to be aware of them. 

Your doctor will speak with you about how to reduce the risk of these complications. If your child follows the treatment plan, including changes to his or her diet and medicines, he or she is less likely to have complications.

Diseases of the heart and circulation 

There is a risk of developing cardiovascular disease (CVD), a group of diseases of the heart and circulation (blood going round the body) – especially in adulthood. In children with CKD, this may be associated with:

  • high blood pressure (hypertension) – this can affect the heart, as well as speeding up the loss of kidney function
  • an imbalance (wrong amounts) of calcium and phosphate – after many years, this can cause the blood vessels to get stiff and develop problems with the blood circulation.

Potassium levels 

Many children need to follow a diet with a low amount of potassium. If there is too much potassium in the blood, this is called hyperkalaemia.

In serious cases, hyperkalaemia can affect the way the heart beats. If this is severe, it can cause a cardiac arrest, a life-threatening emergency in which the heart suddenly stops pumping blood. 

Calcium and phosphate levels 

Many children need to follow a diet with a low amount of phosphate and take medicines that stop phosphate from working. If there is too much phosphate in the blood, this is called hyperphosphataemia

This can lead to muscle cramps, numbness around the mouth or a tingling feeling. In serious cases it can cause problems in the bones (renal bone disease). This may include rickets (the bones become painful, soft and weak) and deformities such as bowed legs or a curved spine.

Hyperphosphataemia can also lead to imbalance of calcium in the blood. Calcium can get trapped in the walls of blood vessels and cause the blood vessels to get stiff, which leads to cardiovascular disease. 

Chronic kidney disease – stages 3b to 5