Nephrotic Syndrome

Overview

Nephrotic (neff-rot-ick) syndrome is a condition in which your kidneys release an excessive amount of protein (proteinuria) in your urine (pee).

Nephrotic syndrome usually results from a problem with your kidneys’ filters (glomeruli). Glomeruli (glo-mare-yoo-lye) are tiny blood vessels in your kidneys. They remove wastes and excess fluids from your blood and send them to your bladder as urine. Common waste products include nitrogen waste (urea), muscle waste (creatinine) and acids.

In healthy kidneys, the glomeruli filter out the waste products. They allow your blood to retain the cells and proteins your body needs to function regularly.

Damaged glomeruli allow blood proteins to leak into your pee, including albumin. If you have nephrotic syndrome, your damaged glomeruli allow three or more grams (g) of protein to leak into your pee over 24 hours. Three grams is a little heavier than a U.S. penny. It’s 20 times the amount of protein that healthy glomeruli allow.

How does nephrotic syndrome affect my body?

If you have nephrotic syndrome, losing different proteins may cause various problems.

Some proteins help prevent blood clots. When you lose those proteins in your pee, blood clots can form.

Immunoglobulins are proteins that help your immune system fight diseases and infections. When you lose immunoglobulins, you’re at a greater risk of general infections that affect different body systems, including:

What are the symptoms of nephrotic syndrome?

Common nephrotic syndrome symptoms include:

Large amounts (greater than 3.5 grams) of the protein albumin in your pee (albuminuria).
High fat and cholesterol levels in your blood (hyperlipidemia).
Swelling (edema), usually in your legs, feet or ankles. Swelling may also occur in your hands or face.
Low levels of albumin in your blood (hypoalbuminemia).
Loss of appetite.
Feeling unwell or sick.
Abdominal pain (pain anywhere from your ribs to your pelvis).
Foamy pee.

Another symptom of nephrotic syndrome is a loss of minerals and vitamins that are essential to your health and development, including calcium and vitamin D. In children with nephrotic syndrome, this may affect their growth. You may develop osteoporosis, which weakens your hair and nails.

What causes nephrotic syndrome?

Kidney diseases often damage your glomeruli. The diseases target your glomeruli, though healthcare providers and medical researchers aren’t sure why. Damaged glomeruli are the primary cause of nephrotic syndrome. These diseases include:

Amyloidosis. This is a disease in which amyloid proteins build up in your vital organs. Amyloidosis most commonly occurs in your kidneys, affecting their ability to filter.
Diabetes-related nephropathy. “Nephropathy” means that your kidney isn’t working properly. In diabetes-related nephropathy, diabetes causes damage or dysfunction to one or more of the nerves in your kidneys. It typically causes numbness, tingling, muscle weakness and pain in your affected area.
Focal segmental glomerulosclerosis (FSGS). In FSGS, scarring affects small areas (segments) of some of your glomeruli. It may cause swelling, kidney failure and loss of proteins in your pee.
Lupus. Lupus is an autoimmune disease that causes inflammation, swelling and pain throughout your body, including your kidneys.
Membranous nephropathy. In membranous nephropathy, your body’s immune system attacks the filtering membranes in your kidneys.
Minimal change disease (MCD). This is a type of nephropathy in which your kidneys aren’t working properly. However, a kidney biopsy shows little or no damage to your glomeruli or kidney tissue. MCD may occur at any age, but it’s most common in children.

How do I take care of myself?

The best way to manage your symptoms is to take your medications as prescribed by your healthcare provider. It’s also a good idea to maintain a diet with appropriate amounts of potassium and protein but low amounts of sodium, saturated fat and cholesterol.