Family Health|Kids and Teens
orthostatic proteinuria|persistent proteinuria|protein / creatinine ratio

Proteinuria in Children

Last Updated June 2023 | This article was created by familydoctor.org editorial staff and reviewed by Deepak S. Patel, MD, FAAFP, FACSM

What is proteinuria in children?

Proteinuria means there’s protein in your child’s urine. All children have a little protein in their urine. But too much may signal a problem with your child’s kidneys. Kidneys are organs that filter out waste, extra fluid, and salt. These wastes leave the body through urine.

Sometimes older children can have orthostatic proteinuria. Orthostatic means “upright.” It’s called “orthostatic proteinuria” because protein goes into the urine only when the child is standing up. Children who have this condition have no kidney damage. But for some unknown reason, they lose protein into the urine during the day when they are active. At night, while they sleep, their kidneys don’t release protein into the urine.

Symptoms of proteinuria in children

You can’t see protein in your child’s urine. However, it can be associated with swelling in his or her eyelids, ankles, and legs. High blood pressure is another sign of this condition. Proteinuria doesn’t cause pain.

What causes proteinuria in children?

Sometimes infection or chemicals damage the kidneys. This affects how well the kidneys work. If your child has an infection, his or her proteinuria will go away once the infection is treated.

Protein in the urine also can be associated with type 1 and type 2 diabetes. Tell your doctor if your child has been excessively thirsty, hungry, unintentionally lost weight, or has fruity-smelling breath. These can be signs of type 1 diabetes.

How is proteinuria in children diagnosed?

Because you can’t see protein in your child’s urine, it must be diagnosed with a urine test. For this test, a sample of your child’s urine will be collected for diagnosis.

After the first test, your doctor may want to recheck your child’s urine for protein. That’s because the protein will often go away on its own (transient proteinuria). If the protein is still high on the second test, your doctor may ask you to collect a 24-hour urine sample from your child. This lets your doctor measure the amount of protein in the urine more accurately.

Your doctor may test your child’s blood. They may also order an ultrasound or CT scan. These two procedures take pictures of your child’s kidneys and surrounding area to look for problems. These procedures aren’t painful.

To diagnose orthostatic proteinuria, your child’s doctor will check 2 urine samples. The first is collected in the morning, right after your child gets up. The second sample is collected throughout the day. The samples are kept in separate containers. If your child has orthostatic proteinuria, the morning sample won’t have protein in it. But the urine collected during the day will have protein in it.

Can proteinuria in children be prevented or avoided?

Proteinuria can’t be prevented or avoided. However, you can practice good kidney health by drinking lots of water every day. This will flush waste out of your kidneys.

Proteinuria in children treatment

If tests show your child has orthostatic proteinuria or only small amounts of protein in their urine, no treatment is needed.

If tests show a large amount of protein in your child’s urine, and they have swelling of the legs and eyelids, your doctor may send them to a kidney specialist. This doctor is called a nephrologist. The nephrologist may perform a kidney biopsy. During this simple surgical procedure, a small piece of kidney tissue is removed. The doctor will look at the piece under a microscope. This may help them find out what is causing the protein in your child’s urine. Once the doctor knows why it’s happening, they can treat the problem.

Living with proteinuria in children

If your child has proteinuria in the urine, their activity level won’t need to change. They may feel uncomfortable because of swollen eyelids, ankles, or legs, but your doctor can treat those issues.

Questions to ask your doctor

  • Could swelling in the eyelids, ankles, and legs be caused by something else?
  • Is proteinuria fatal if left untreated?
  • Is there anything I can do to make proteinuria go away?
  • Can the condition be caused by eating too much protein?

Resources

National Kidney Foundation: Proteinuria in Children

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