Proteinuria

Proteinuria can be classified into three kinds:

• Transient proteinuria. Also called intermittent proteinuria, this is a very common type of proteinuria. In this kind, larger than normal amounts of protein are found in the urine for a short period under conditions of stress, such as fever, significant illness or severe exercise. This type of proteinuria resolves on its own without any problems and does not indicate kidney damage.
• Orthostatic proteinuria. In this type, children lose protein in the urine when they are standing up and walking around, but not when they are lying flat. This is common in adolescents and does not indicate renal damage or problems. To test for this kind of proteinuria, your child's doctor may request that you bring in either a first morning urine sample or a 24-hour collection of urine.
• Persistent proteinuria. This is when large amounts of protein are found in the urine at all times. This kind of proteinuria always needs to be analyzed by your child's doctor through detailed blood testing, urine testing and/or renal ultrasound. It can be found in several types of kidney disease, and the underlying cause needs to be identified so that specific treatment can be started.

In its early stages, proteinuria has no signs or symptoms. Once the condition progresses, you may notice that your child's urine looks foamy. Your child may also experience edema (swelling of the hands, feet, abdomen or face caused by excess fluid in the body).

Diagnosis of Proteinuria

Doctors at Riley at IU Health perform the following tests and exams to diagnose proteinuria:

• Urinalysis. A laboratory urine test (urinalysis) is the only definitive way to determine if your child has proteinuria before major kidney damage occurs.
• Urine protein quantification. This test can determine the exact amount of protein present in the urine. It is typically done by either a split 24-hour urine collection or first morning urine testing.
• Blood tests. The pediatric nephrologist may order specific blood tests for your child to look into the cause of proteinuria.
• Renal ultrasound. This is often done to look at the structure and anatomy of the kidneys.
• Renal biopsy. A renal (kidney) biopsy may need to be done to determine the exact cause of protein in the urine if urine and blood tests cannot find the cause. It is important to find the cause so proper treatment can be started.

If your child is diagnosed with proteinuria, it is important that you work with your child's doctor to manage the condition so that it can be properly treated.