Under normal condition, there are only small amounts of protein in urine. When the protein in urine is above 150 mg, it is called proteinuria. For teenagers, the normal urine protein level is higher and its upper limit reaches 300 mg/24 hours. Protein in urine is a common symptom of Kidney Disease. However, can protein in urine certainly prove that you have Kidney Disease? Of course, it can not.
Clinically, proteinuria includes two types: physiological and pathologic
proteinuria. Physiological proteinuria is not caused by diseases and most of
them are transient. It mainly found in the following cases:
1. Orthostatic proteinuria
It is common in teenagers. When standing or walking, they often have protein
in urine, but the protein disappears when they lie down. They do not have edema,
hematuria, and high blood pressure and so on and the protein in urine is less
than 1 gram in 24 hours. This kind of proteinuria does not need treatment at
2. Functional proteinuria
Functional proteinuria is caused by some stresses such as high fever,
intensive exercise, colds and so on. These stress factors may cause glomerular
filtration rate to rise for a short time. Once the stress factors are
eliminated, the protein in urine will disappear. In this case, the protein in
urine is less than 0.5 grams in 24 hours.
Pathologic proteinuria is persistent. If the test result of urine protein is
still positive after several tests, you should go to see a nephrologist at once.
Pathological proteinuria is common in glomerular diseases, renal interstitial
diseases and other systemic diseases.
Once you are diagnosed with proteinuria, you should find out the fundamental
causes and then receive relative treatments.