Proteinuria in Children

What is proteinuria in children?

Proteinuria is the presence of protein in your child’s urine. All children have trace amounts of protein in their urine. Too much means your child’s kidneys may not be working properly. Your kidneys are supposed to filter out waste, extra fluid, and salt. These wastes leave the body in urine.

Another type of proteinuria in older children is orthostatic proteinuria. Orthostatic means “upright.” It is 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 let any protein into the urine.

Symptoms of proteinuria in children

You cannot see protein in your child’s urine. However, it can be associated with swelling in your child’s 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 cannot see protein in your child’s urine, it must be diagnosed with a urine sample. The sample will be sent to a lab for diagnosis. Your doctor may want to recheck your child’s urine for protein because it will often go away on its own (transient proteinuria). If it is still high, 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 also may do some blood tests.

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.

Here’s how to do your child’s 24-hour urine collection. For children who are potty-trained, start the collection on a day when your child doesn’t go to school. Weekends are good. When your child gets out of bed in the morning, have him or her urinate into the toilet. This urine is not saved. Flush it down the toilet. Write down the exact time your child urinates.

After this, whenever your child needs to urinate, have your child urinate in the special container the doctor or the laboratory provides. For girls, collect the urine in a urine “hat” (a specimen collection device). Pour it into the special container. You don’t need to mark the times when these urine samples are collected. Be sure to wash your hands after handling the container.

It’s important to collect all the urine your child produces all day and night. The next morning, wake your child up the same time as the previous day. Have your child urinate into the container one last time. This ends the 24-hour collection. Now write the date and the time on the container label. Bring the container to the lab on this day. Bacteria can grow in urine at room temperature. Keep the urine in a refrigerator until you deliver it to the lab.

Can proteinuria in children be prevented or avoided?

Proteinuria cannot be prevented or avoided. However, good kidney health requires lots of water. Regularly drinking water will flush out waste from your kidneys.

Proteinuria in children treatment

If your child has orthostatic proteinuria or only small amounts of protein in the urine, no treatment is needed. If there is a large amount of protein in your child’s urine and has swelling of the legs and eyelids, your doctor may send your child to a kidney specialist. This is called a nephrologist. The nephrologist may perform a kidney biopsy. A small piece of kidney tissue is removed during a simple surgical procedure. Your doctor will look at the sample at under a microscope. When your doctor finds out what causes the protein in your child’s urine, he or she can treat the problem. Treatment will depend on whether it’s an infection or an injury. Each will require different methods of treatment.

Living with proteinuria in children

If your child has proteinuria in the urine, it will not affect his or her activity. You do not need to restrict your child’s activities. Having to collect a urine sample is time consuming. Swelling in the eyelids, ankles, and legs can be uncomfortable but can be treated.

Questions to ask your doctor

  • Could swelling in the eyelids, ankles, and legs be caused by something else?
  • Is untreated proteinuria fatal?
  • Can the condition be caused by eating too much protein?