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" 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.
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.