What effect does nephrosis have on total protein levels?

Nephrosis, particularly in the context of nephrotic syndrome, leads to a significant decrease in total protein levels. This occurs primarily due to the increased urinary loss of protein, especially albumin, as the glomerular filtration barrier becomes compromised. In healthy kidneys, this barrier prevents the leakage of large molecules such as proteins into the urine. However, in nephrotic syndrome, the damage to the glomeruli results in proteinuria, which is the abnormal excretion of protein in the urine.

As proteins are lost in urine, the serum levels of total protein decline, particularly impacting the albumin concentration. This decrease can subsequently lead to hypoalbuminemia, characterized by low levels of albumin in the blood, and often results in edema due to a decrease in oncotic pressure. Thus, the correct answer reflects the direct association between nephrosis and reduced total protein levels in the bloodstream.