Nephrotic syndrome happens when there's too much protein in urine (pee) because
of a kidney problem. This causes:
swelling in parts of the body like the face, hands, belly, and feet
sudden weight gain
Most of the time, nephrotic syndrome goes away with medicine, and kids outgrow
it by the time they're teens.
What Causes Nephrotic Syndrome?
Nephrotic (neh-FROT-ik) syndrome happens when tiny filters in the kidneys
called glomeruli (gluh-MARE-you-lie) leak too much protein into urine. It can happen
at any age, but is most common in kids 1–6 years old. It affects boys more than
What Are the Signs & Symptoms of Nephrotic Syndrome?
Swelling and weight gain tend to be the most common signs. Swelling happens because
too many fluids and salt build up in the body. Extra fluids can cause weight gain.
Parents might notice their child quickly outgrows clothes and shoes.
Swelling most often happens in the:
face, especially around the eyes (this is most noticeable in the morning)
ankles and feet, especially after sitting or standing a long time
Other common signs include loss of appetite, peeing less often, and pee that looks
dark and foamy.
Some kids don't have any symptoms. They may learn they have nephrotic syndrome
when a routine urine test finds the condition.
What Happens in Nephrotic Syndrome?
Glomeruli are balls of tiny blood vessels (capillaries) that help remove waste
products from the blood. When the filters stop working correctly, too much protein
gets into pee.
Protein helps hold fluids in the blood. With less protein in the blood, fluids
can move to other parts of the body and cause swelling in the face, belly, hands,
arms, and feet.
Many things can damage the glomeruli and cause nephrotic syndrome. But in kids
it's usually due to minimal change disease. The damage to the glomeruli
is so small (or "minimal") that it can be seen only under a strong microscope called
an electron microscope.
Why kids get minimal change disease isn't always known. It is believed to be due
to an immune system problem.
Often, it happens after an infection. Most kids outgrow minimal change disease by
their teen years, with no kidney damage.
Rarely, kids can get other types of nephrotic syndrome due to things like:
cancer and tumors
taking too many over-the-counter medicines like ibuprofen
Doctors diagnose nephrotic syndrome with urine tests and blood tests.
If a child has nephrotic syndrome, the doctor will look for the cause, then decide
how best to treat it. The doctor also might:
order other blood tests
take a tiny sample of kidney tissue (a kidney biopsy) to
test for specific causes of the condition
How Is Nephrotic Syndrome Treated?
Nephrotic syndrome is almost always treatable, but the treatment depends on the
cause. Kids with nephrotic syndrome usually are treated by a nephrologist
(a doctor who specializes in kidney problems).
To treat minimal change disease, the doctor will prescribe:
Prednisone. This medicine works well to treat nephrotic syndrome,
but can sometimes have side effects. The doctor may prescribe other medicines to ease
or prevent them.
A diuretic. This makes a child pee more often, which can help
control the swelling until protein levels return to normal.
Kids should eat a low-salt diet to help ease swelling. A low-protein diet isn't
necessary. For other dietary advice, talk to a doctor or dietitian.
If prednisone treatment doesn't lower the protein levels in the urine, the doctor
will do a kidney biopsy to look for other causes of the condition.
What Else Should I Know?
Minimal change disease causes most cases of nephrotic syndrome in kids. Those who
get prednisone usually respond well, and the problem goes away by the time they're
teens. In the meantime, kids might need to take medicines for a few months or more.
Sometimes, a child will have a relapse. This means the nephrotic syndrome comes
back after going away. In this case, treatment starts again until the child outgrows
the condition or it improves on its own.
The sooner treatment for nephrotic condition starts, the better. If your child
shows any signs of the condition, call your doctor so it can get checked out right