Nephrotic syndrome: heavy protein loss, swelling and what causes it

Dr. Joan J. Morales Lappot, MD
3 min read · Leer en español

In briefNephrotic syndrome is not one disease but a pattern: the kidney filters become so leaky that large amounts of protein spill into the urine.

The pattern

Heavy protein in the urine (more than about 3.5 grams a day)
Low albumin in the blood
Swelling, often around the eyes in the morning and in the legs later in the day
High cholesterol
Very foamy urine

Common causes in adults

Diabetic kidney disease
Membranous nephropathy, an immune condition often identified with a blood test called anti-PLA2R
Focal segmental glomerulosclerosis (FSGS)
Minimal change disease
Less often: lupus, amyloidosis, infections or certain medicines

A kidney biopsy is often needed to know which one it is, because the treatment depends on the cause.

Get care right away if:

You have sudden shortness of breath or chest pain
One leg becomes swollen and painful
You make much less urine than usual

Call 911 for chest pain, trouble breathing or fainting.

Treatment

Treatment targets the cause, sometimes with medicines that calm the immune system. Supportive care helps everyone: less salt, water pills for swelling, medicines that reduce protein leak, and cholesterol treatment. Because albumin also helps keep blood from clotting too easily, some people with very low levels need a blood thinner for a while.

Bottom line: Nephrotic syndrome sounds intimidating, but many causes respond well to treatment. The key step is finding out which one you have.

Questions about your kidneys?Call (954) 989-9553