In nephrotic syndrome, the kidneys leak too much protein into urine, leading to a drop in the levels of protein in the blood. This causes swelling in the body, especially in the face, legs and feet.

Children usually need to stay in hospital for monitoring and treatment the first time this happens.

About nine in ten children with nephrotic syndrome have a type that can be treated with a steroid medicine. This is steroid-sensitive nephrotic syndrome (SSNS), because it is “sensitive” to steroids. It is sometimes called minimal change nephrotic syndrome (MCNS) or minimal change disease.

In a few children, the nephrotic syndrome does not get better with steroids, or keeps coming back (nephrotic syndrome, frequently relapsing).

About the urinary system

The urinary system gets rid of things that the body no longer needs, so that we can grow and stay healthy.

The kidneys are bean-shaped organs. They filter blood and remove extra water and waste in urine (wee). Normally there are two kidneys. They are at the back on either side of our spine (backbone), near the bottom edge of our ribs.

The two ureters are long tubes that carry urine from the kidneys to the bladder.

The bladder is a bag that stores urine until we are ready to urinate (wee). It sits low down in the pelvis.

The urethra is a tube that carries urine from the bladder to the outside of the body. We urinate through the opening at the end of the urethra.

Nephrotic syndrome: symptoms and complications

The main symptom of nephrotic syndrome is swelling in the body – this is called oedema. In children, the swelling is mainly around the eyes and in the legs and feet.

The swelling happens because the kidneys leak a lot of protein in the urine (which is called proteinuria). You cannot usually see the protein, though it can be found a simple urine test.

A small number of children have other symptoms such as a very swollen tummy (ascites) or breathlessness. Complications, or further problems, are extremely rare.

Causes of nephrotic syndrome

Nephrotic syndrome is rare – about 1 in 50,000 children get nephrotic syndrome each year. It affects more boys than girls. It can happen in people of all ages, though often starts when a child is between 2 and 5 years old.

Many cases are linked to the immune system, which normally protects the body against disease and infection.

There are different types of nephrotic syndrome. These are described by whether steroid medicine will treat the symptoms, or what is causing the symptoms.

It is often not possible to find out which type your child has until after they have taken a course of steroids.

Nephrotic syndrome: tests and diagnosis

Your doctor can diagnose (identify) nephrotic syndrome by doing a physical examination, asking about the symptoms and doing a urine test to look for protein. Your child may need other tests, such as blood tests.

Nephrotic syndrome: treatment

Your child will probably need to be admitted to hospital for a few days or longer.

He or she will need to take a steroid medicine – usually prednisolone. Most children start to get better after taking steroids for 1 to 2 weeks. In about 9 in 10 children, the nephrotic syndrome will have responded to the steroids within 4 weeks.

Some children need to take other medicines to help prevent or treat infections or to reduce the oedema (swelling).

Monitoring treatment

You will need to test your child’s urine for protein every morning – while your child is on steroids, and then for at least 6 months. A nurse will show you how to do this.

  • If there is no or very little protein in the urine and the swelling goes down, the nephrotic syndrome has gone into remission.
  • If there is protein in the urine again, this is a relapse. You will need to contact your doctor, and your child may  need another course of steroid medicines.

About the future

Relapses

About half of children with SSNS will have at least one relapse, and many have two or three relapses. In most children, the SSNS tends to relapse less often as they grow into their teenage years. It is rare that SSNS continues to relapse in adulthood.

If your child’s nephrotic syndrome keeps coming back, this is called frequently relapsing nephrotic syndrome. Your doctor will consider the best treatment for your child.

Follow up

All children with nephrotic syndrome need to go back to the hospital or clinic for follow-up appointments to check for any health problems. Remember to bring the results from your urine testing.

Kidney problems

A very small number of children with nephrotic syndrome have more serious problems with their kidneys. Your doctor will refer your child to a paediatric nephrologist, a children’s kidney doctor, for more specialist treatment.

More information

  • About the urinary system and kidneys

    If your child has a health condition that affects their kidneys or another part of the urinary system, you may wish to find out more.

  • Nephrotic syndrome: frequently relapsing

    If your child's nephrotic syndrome keeps coming back, this is said to be frequently relapsing and may need further treatment.

  • FSGS and IgM nephropathy

    These conditions cause nephrotic syndrome in children, where the kidneys leak too much protein into the urine and lead to swelling in the body.