PROTEINURIA - RESOURCE CENTRE

WHAT IS PROTEINURIA?

Protein is an essential substance of the body and is mainly made up of amino acids. It performs various key functions in the body; they keep our immunity system strong enough to fight common infection, help digestions, carry various substances around the body and in aids in blood clotting. Protein is normally found in the blood system of the body and should not be present in the urine.

The kidneys are made up of millions of tiny filtering systems known as glomeruli. Most proteins are too large to pass through the glomeruli into the urine. The glomeruli are negatively charged, so they repel the negatively charged proteins. Thus, a size and charge barrier keeps protein molecules from entering the urine. But when the glomeruli are damaged, proteins of various sizes pass through them and are excreted in the urine.

Proteinuria is the condition where the protein leaks out from the kidney into the urine and the urine contains an abnormal amount of protein. In early stage of this condition, albumin leaks out first and when the quantity is small and cannot be detected by conventional methods used for urine protein detection, this is called microalbuminuria. When the condition is more advanced, larger molecules other than albumin leak out and we term this state collectively as “proteinuria”.

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Expert Author:

Dr Roger Tan, Consultant Nephrologist