Nephrotic syndrome: MedlinePlus Mobile Medical Encyclopedia

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Causes
Nephrotic syndrome is caused by different disorders that damage the kidneys. This damage leads to the release of too much protein in the urine.

The most common cause in children is minimal change disease. Membranous glomerulonephritis is the most common cause in adults.

This condition can also occur from:

Cancer
Diseases such as diabetes, systemic lupus erythematosus, multiple myeloma, and amyloidosis
Genetic disorders
Immune disorders
Infections (such as strep throat, hepatitis, or mononucleosis)
Use of certain drugs

It can occur with kidney disorders such as:

Focal and segmental glomerulosclerosis
Glomerulonephritis
Mesangiocapillary glomerulonephritis

Nephrotic syndrome can affect all age groups. In children, it is most common between ages 2 and 6. This disorder occurs slightly more often in males than females.

Symptoms
Swelling (edema) is the most common symptom. It may occur:

In the face and around the eyes (facial swelling)
In the arms and legs, especially in the feet and ankles
In the belly area (swollen abdomen)

Other symptoms include:

Foamy appearance of the urine
Poor appetite
Weight gain (unintentional) from fluid retention

Exams and Tests
The doctor will perform a physical exam. Laboratory tests will be done to see how well the kidneys are working. They include:

Albumin blood test
Blood chemistry tests such as basic metabolic panel or comprehensive metabolic panel
Blood urea nitrogen (BUN)
Creatinine - blood test
Creatinine clearance - urine test
Urinalysis

Fats are often also present in the urine. Blood cholesterol and triglyceride levels may be high.

A kidney biopsy may be needed to find the cause of the disorder.

Tests to rule out various causes may include the following:

This disease may also change the results of the following tests:

Vitamin D level
Serum iron
Urinary casts

Treatment
The goals of treatment are to relieve symptoms, prevent complications, and delay kidney damage. To control nephrotic syndrome, you must treat the disorder that is causing it. You may need treatment for life.

Treatments:

Keep blood pressure at or below 130/80 mmHg to delay kidney damage. Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are the medicines most often used. ACE inhibitors may also help decrease the amount of protein lost in the urine.
You may take corticosteroids and other drugs that suppress or quiet the immune system.
Treat high cholesterol to reduce the risk of heart and blood vessel problems. A low-fat, low-cholesterol diet is usually not very helpful for people with nephrotic syndrome. Medications to reduce cholesterol and triglycerides (usually statins) may be needed.
A low-salt diet may help with swelling in the hands and legs. Water pills (diuretics) may also help with this problem.
Low-protein diets may be helpful. Your health care provider may suggest eating a moderate-protein diet (1 gram of protein per kilogram of body weight per day).
You may need vitamin D supplements if nephrotic syndrome is long-term and not responding to treatment.
Blood thinners may be needed to treat or prevent blood clots.

Outlook (Prognosis)
The outcome varies. The condition may be acute and short-term or chronic and not respond to treatment. The complications that occur can also affect the outcome.

Some people may eventually need dialysis and a kidney transplant.

When to Contact a Medical Professional
Call your health care provider if:

You have symptoms of nephrotic syndrome
Nephrotic syndrome does not go away
New symptoms develop, including:

Go to the emergency room or call the local emergency number (such as 911) if you have convulsions.

Prevention
Treating conditions that can cause nephrotic syndrome may help prevent the syndrome.

Alternative Names
Nephrosis

References
Appel GB. Glomerular disorders and nephrotic syndromes. In: Goldman L, Ausiello D, eds. Cecil Medicine . 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 122.

Nachman PH, Jennette JC, Falk RJ. Primary glomerular disease. In: Brenner BM, ed. Brenner and Rector's The Kidney . 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 30.

Update Date: 9/20/2011
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Herbert Y. Lin, MD, PhD, Nephrologist, Massachusetts General Hospital, Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.