What is it?

Proteinuria refers to abnormal levels of protein in the urine and is usually a sign of kidney damage. Normally, the glomeruli in the kidneys filter waste and excess water from the blood to the urine, but not proteins. If proteins do pass to the urine, the tubules are supposed to reabsorb it. If the glomeruli or the tubules in the kidney are damaged, proteinuria may occur. More specifically, causes for proteinuria include dehydration, kidney stones, chronic kidney disease, diabetes, high blood pressure, lupus, glomerulonephritis, multiple myeloma, cardiovascular disease, poisoning, trauma, and kidney cancer. Proteinuria is diagnosed in a urine test and treatment depends on the underlying cause.