Nephrotic Syndrome
Nephrotic syndrome may occur when the filtering units of the kidney are damaged. This damage allows protein normally kept in the plasma to leak into the urine in large amounts, which reduces the amount of protein in your blood. Since the protein in the blood helps keep fluid in the bloodstream, some of this fluid leaks out of the bloodstream into your tissues, causing swelling, called edema. The swelling may be most noticeable in your legs after you have been standing and around your eyes when you first get up in the morning. Eventually, the swelling in your legs may be there all the time, and it may also occur in other parts of your body. You may notice that your urine foams more than usual because of the amount of protein in it.