Proteinuria means there is too much protein in the urine. Healthy kidneys allow only a very small amount of protein to pass from the blood into the urine.
Proteinuria may suggest that the kidneys are sick.
Measuring protein in the urine is one way to check on the health of the kidneys. Fortunately, many children have only temporary proteinuria and do not have a kidney disease.
Testing for proteinuria
A urinalysis is the easiest way to test for proteinuria. A urinalysis is done by dipping a chemically treated paper strip into a urine sample. If the paper strip changes to a certain color, that means there's protein in the urine. Then, other tests can be used to find the exact amount of protein. This can be done by sending a urine sample to a lab.
Harmless types of proteinuria
Many children with proteinuria do not have kidney disease. Orthostatic proteinuria and temporary proteinuria, for example, are common causes of proteinuria in children without kidney disease.
Orthostatic proteinuria
"Orthostatic" is the medical term for "upright" (standing). Children with orthostatic proteinuria spill protein into the urine only when they are standing up, but not while they are laying down.
A child is diagnosed with orthostatic proteinuria when their daytime urine has increased ed levels of protein, but their first morning urine sample is normal. The first morning urine sample is normal because at night, while the child is laying down and sleeping, their kidneys do not leak too much protein into the urine.
Children who have orthostatic proteinuria do not have kidney disease and do not need any treatment or follow-up. This kind of proteinuria is a variation of normal.
Temporary proteinuria
Some children may have increased protein in the urine during times of illness, fever, exercise or other kinds of physical stress. This type of proteinuria is also a variation of normal. It is important to recheck the amount of protein in the urine of these children after they are well or before exercise to make sure that proteinuria is not still present.
Proteinuria and kidney disease
Proteinuria that is not orthostatic or temporary may occur in children with kidney disease. Children with kidney disease may also have high blood pressure or blood in the urine. Severe proteinuria may cause swelling of the face, stomach or legs.
Swelling due to proteinuria happens in a kidney problem called nephrotic syndrome. Children with proteinuria may have other symptoms such as rash or joint pain due to the disease causing the proteinuria.
A pediatric nephrologist is a doctor who cares for children with kidney disease and evaluates and treats children with proteinuria. Children with proteinuria often need blood tests to check on the health of their kidneys and to look for the cause of the kidney disease.
The pediatric nephrologist may need to do a kidney biopsy to determine the cause of the proteinuria and the best way to treat your child. A kidney biopsy uses a needle to take a tiny sample of kidney tissue. It is then examined under a microscope.
The pediatric nephrologist often uses medications to treat children with kidney disease causing proteinuria. Changing the protein in your child's diet is not necessary and is almost never recommended.
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Additional Information:
Source
American Academy of Pediatrics, American Society of Pediatric Nephrology and the National Kidney Foundation Patient Education Collaborative (Copyright © 2022)
The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.