What Is Nephrotic Syndrome?

Nephrotic syndrome isn’t a disease. It’s a group of symptoms that can appear if your kidneys aren’t working right.

Small blood vessels in your kidneys function as a filter, clearing out waste and extra water from your blood. That waste and water ends up in your bladder and leaves your body as urine. These vessels are part of what’s called “glomeruli,” the filtering part of your kidney.

When they’re damaged, too much protein slips through the filters into your urine. The result is nephrotic syndrome.

Nephrotic syndrome can affect both adults and children. And there are treatments for it.


You might have a condition that affects only your kidneys. Doctors call that a “primary” cause of nephrotic syndrome.

Or you might have an issue with another part of your body that also affects your kidneys. That’s called a “secondary” cause of nephrotic syndrome.

Some of the conditions that can damage your glomeruli include:

Minimal change disease, which is the main cause of nephrotic syndrome in children. Doctors don’t know why this disease stops the kidneys from working properly. Kidney tissue from people with this disease looks relatively normal under a microscope.

Focal segmental glomerulosclerosis, or FSGS, is a disease that scars the glomeruli. It’s the most common primary cause of nephrotic syndrome in adults.

Membranous nephropathy, in which the membranes of the glomeruli thicken. Researchers don’t know why this happens, exactly, but it’s been linked to cancer, malaria, hepatitis B, and lupus.

Diabetes, which is the most common secondary cause of nephrotic syndrome in adults. It can cause kidney damage, known as diabetic nephropathy.

Lupus (systemic lupus erythematosus), a chronic disease of the immune system, can seriously damage the kidneys.

Amyloidosis, which happens when you have a buildup of substances called amyloid proteins in your blood. This can damage your kidneys.


There are four main signs or symptoms make up nephrotic syndrome. They are:

  1. Too much protein in your urine. Doctors call this proteinuria.
  2. High fat and cholesterol levels in the blood. The medical term for it is “hyperlipidemia.”
  3. Swelling of your legs, feet and ankles, and sometimes of your hands and face. This is called edema.
  4. Low levels of albumin in your blood. Your doctor may call this “hypoalbuminemia.”


Who’s at Risk?

Certain conditions -- such as diabetes, lupus, and amyloidosis -- make you more likely to get nephrotic syndrome.

You also face a greater risk if you take nonsteroidal anti-inflammatory drugs (NSAIDs) regularly.

Some infections can raise the chances you’ll get nephrotic syndrome. They include:

  • Hepatitis B and C
  • HIV
  • Malaria
  • In children, untreated strep infection

If you think you have symptoms of nephrotic syndrome, make an appointment with your doctor.


You’ll take a urine test, which will measure how much protein your kidneys are filtering out. You may also get blood tests that check on other kidney functions.

Your doctor might also check for diseases that could be a secondary cause of nephrotic syndrome, such as diabetes.

Some people will need a kidney biopsy, which requires taking a tissue sample for study under a microscope.


Without treatment, nephrotic syndrome can cause other problems, including:

  • Blood clots. These may form because you’ve lost too much protein from the blood, affecting your body’s ability to prevent clots.
  • High cholesterol and triglycerides
  • High blood pressure
  • Kidney failure, because your damaged kidneys can no longer remove waste product from your bloodstream on their own
  • Infections such as pneumonia and meningitis because your body loses infection-fighting proteins called immunoglobulins


Your doctor’s plan will depend on the cause of your nephrotic syndrome. If a different condition is to blame, that will be the first thing to treat. Lowering your cholesterol and blood pressure as well as reducing edema may be key goals.

Medicines you might take include:

You may need to cut down on salt to reduce swelling. Your doctor may also suggest you eat a diet low in saturated fats and cholesterol.

If your nephrotic syndrome doesn’t get better with these treatments, you might need dialysis, a treatment in which a machine filters your blood because your kidneys can’t do the job.


Can I Prevent It?

You can’t prevent some causes of nephrotic syndrome. But you can take action to avoid damage to your glomeruli:

  • Manage high blood pressure and diabetes, if you have them
  • Be sure to get vaccines for common infections, especially if you work around people who have hepatitis or other diseases
  • If your doctor prescribes antibiotics, take them as directed and finish every prescription, even if you start to feel better
WebMD Medical Reference Reviewed by Minesh Khatri, MD on January 19, 2017



American Kidney Fund: “Nephrotic syndrome.”

UCLA Health Encyclopedia: “Nephrotic Syndrome.”

NIH National Institute of Diabetes and Digestive and Kidney Diseases: “Childhood Nephrotic Syndrome.”

Mayo Clinic: “Diseases and Conditions -- Nephrotic syndrome.”

NIH National Institute of Diabetes and Digestive and Kidney Diseases: “Nephrotic Syndrome in Adults.”

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