Nephrotic syndrome is a kidney disorder that causes the body to excrete too much protein in the urine, leading to symptoms such as swelling in the face, ankles, and feet, fatigue, foamy urine, and abdominal pain.
Nephrotic syndrome can be triggered by different factors that damage the glomeruli, which are the kidney structures responsible for filtering substances from the blood. It may occur due to conditions like glomerulonephritis, diabetes, lupus, viral infections, or the use of certain medications.
Treatment for nephrotic syndrome should be guided by a urologist or nephrologist and focuses on relieving symptoms, treating the underlying cause, and preventing kidney damage. This usually involves medications to lower blood pressure and reduce swelling and inflammation, in addition to following a diet low in sodium and fat.
Main symptoms
The most common symptoms of nephrotic syndrome include:
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Swelling in the ankles and feet;
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Swelling in the face, especially around the eyelids;
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General discomfort or malaise;
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Abdominal pain and bloating;
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Loss of appetite;
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Fatigue;
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Foamy urine.
Nephrotic syndrome may also cause changes in blood pressure, shortness of breath due to fluid buildup in the lungs, high triglyceride and cholesterol levels, and malnutrition. In addition, it can increase the risk of blood clots and infections due to a weakened immune system.
Nephrotic syndrome in children
Nephrotic syndrome in children is relatively rare and can develop as a result of infections, blood disorders, long-term use of certain medications, or congenital conditions in which a child is born with kidney abnormalities that cause the disorder.
Main symptoms
The main symptom in children is facial swelling, while in other parts of the body may appear later. Other signs include excessive tiredness and foamy urine due to high levels of protein.
When to see a doctor
If symptoms suggest nephrotic syndrome, it’s important to see a pediatrician to confirm the diagnosis and start treatment, which typically involves the use of corticosteroids.
Confirming a diagnosis
Diagnosis of nephrotic syndrome should be made by a urologist, nephrologist, or general practitioner. In children, a pediatrician usually makes the diagnosis.
Diagnostic tests
Diagnosis is based on evaluation of symptoms as well as results of diagnostic tests, such as:
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A 24-hour urine test to measure protein loss;
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Blood tests to check albumin, fat, and cholesterol levels.
Main causes
Nephrotic syndrome can be caused by several health conditions, including:
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Diabetes;
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Systemic lupus erythematosus (lupus);
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Viral or bacterial infections;
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Cancer;
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Genetic disorders;
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Immune system abnormalities.
It may also result from the long-term use of certain medications, especially nonsteroidal anti-inflammatory drugs (NSAIDs).
In some cases, nephrotic syndrome is present from birth and is referred to as congenital nephrotic syndrome.
Treatment options
Treatment for nephrotic syndrome should always be supervised by a urologist or nephrologist and usually involves medications to relieve symptoms, control inflammation, and prevent complications.
Commonly used medications
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Blood pressure medications, such as ACE inhibitors like lisinopril or enalapril, or angiotensin II receptor blockers (ARBs) like losartan or valsartan, which help reduce blood pressure and protein loss in the urine;
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Diuretics, such as furosemide or spironolactone, to increase urine output and decrease swelling;
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Corticosteroids, to suppress immune activity and reduce inflammation in the kidneys.
In some cases, additional medications may be prescribed to prevent blood clots, such as heparin or warfarin, or to reduce cholesterol levels, such as atorvastatin or simvastatin, helping prevent complications like embolism or kidney failure.
Dietary changes
A diet for nephrotic syndrome should be balanced and nutritious, providing adequate but not excessive protein, moderate potassium, and low sodium to help control blood pressure and fluid retention. In addition to limiting salt during cooking, it’s important to avoid sodium-rich foods such as canned, frozen, and processed foods.
Because nephrotic syndrome can also increase cholesterol and triglyceride levels, it’s important to limit foods high in saturated fat, such as red meat, fried foods, aged or yellow cheeses, whole milk and full-fat dairy products, processed meats, and industrialized or packaged foods.