What is nephrotic syndrome?
Nephrotic syndrome is a disorder that indicates damaged kidneys. It refers to a group of symptoms, including protein in the urine, low blood protein, and high cholesterol.
Nephrotic syndrome can occur in anyone. The syndrome arises for many reasons, including a condition known as minimal change disease in children and glomerulonephritis (kidney inflammation) in adults. Nephrotic syndrome can also be caused by infection, medication side effects, heredity, cancer, and autoimmune disorders, such as diabetes and lupus.
Other symptoms and signs of nephrotic syndrome are foamy urine, unexplained weight gain, loss of appetite, high blood pressure, and edema (swelling), especially in the face, feet and abdomen. Treatment for nephrotic syndrome is aimed at controlling these symptoms.
Nephrotic syndrome may be treated with blood pressure medications, such as angiotensin receptor blockers and angiotensin-converting enzyme inhibitors. Immunosuppressant drugs and drugs to treat high cholesterol may also be used, depending upon the cause. Proper medical treatment may help prevent further damage to the kidneys.
Seek immediate medical care (call 911) for serious symptoms of nephrotic syndrome, such as convulsions or difficulty breathing.
Seek prompt medical care for persistent or bothersome symptoms of nephrotic syndrome, including fever, headache, painful urination, or changes in amount and frequency of urination.
What are the symptoms of nephrotic syndrome?
Symptoms of nephrotic syndrome are related to improper functioning of the kidneys, leading to improper handling of body waste. Nephrotic syndrome is often progressive (gets worse with time), so early stages of the syndrome may be symptomless. In late stages, nephrotic syndrome may progress to kidney failure.
Common symptoms of nephrotic syndrome
You may experience nephrotic syndrome symptoms daily or only occasionally. Any of these symptoms can be severe:
- Edema (swelling) of the face, limbs, or abdomen
- Foamy urine
- Loss of appetite
- Unexplained weight gain
Other symptoms of nephrotic syndrome
As nephrotic syndrome progresses, other symptoms may develop including:
Serious symptoms that might indicate a life-threatening condition
In some cases, nephrotic syndrome can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:
What causes nephrotic syndrome?
Nephrotic syndrome is caused by damage to the kidneys, generally as the result of another disorder. The part of the kidney that becomes damaged is called the glomerulus, or the filtering unit of the kidney. When glomeruli are damaged, they cannot handle waste in the bloodstream properly, so they fail to block the passage of protein into the urine. The body then retains excess water, leading to swelling.
Common causes of nephrotic syndrome
Nephrotic syndrome generally results from another disorder that damages the kidneys, such as:
Amyloidosis (rare immune-related disorder characterized by protein buildup in organs and tissues that can cause serious complications)
Certain infectious diseases such as viral hepatitis
Certain medications, especially nonsteroidal anti-inflammatory drugs (NSAIDs)
Diabetes (chronic disease that affects your body’s ability to use sugar for energy)
Glomerulonephritis (kidney inflammation)
Glomerulosclerosis (kidney scarring)
Minimal change disease (kidney disease in which the kidneys appear microscopically normal)
Multiple myeloma (cancer of plasma cells in the bone marrow)
Other autoimmune disorders
Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
What are the risk factors for nephrotic syndrome?
A number of factors increase the risk of developing nephrotic syndrome. Not all people with risk factors will get nephrotic syndrome. Risk factors include:
Certain cancer medications
Chronic painkiller abuse
Family history of autoimmune disorders
Personal history of autoimmune disorders
How is nephrotic syndrome treated?
In some cases, nephrotic syndrome may be symptomless or mild and not require treatment. If symptoms appear, however, it is important to treat them because further damage to the kidneys can occur over time. The most important symptom to treat is high blood pressure. Controlling autoimmune symptoms and lowering blood cholesterol are also important goals of treating nephrotic syndrome.
Medications for nephrotic syndrome
Nephrotic syndrome symptoms are treated with a variety of medications including:
Blood pressure medications, such as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, which prevent further damage to the glomeruli
Blood thinners, which prevent clots from forming
Cholesterol-reducing medications such as statins, which control blood cholesterol levels
Corticosteroids, which control inflammation
Diuretics, which reduce swelling
Vitamin supplements such as vitamin D, which replace lost vitamins and minerals
Other treatments for nephrotic syndrome
In addition to medication, other treatments may be used to help control the symptoms of nephrotic syndrome including:
Dietary modification such as salt reduction to reduce swelling
Low protein diets to prevent protein accumulation
What are the potential complications of nephrotic syndrome?
Nephrotic syndrome can be acute and have only a few symptoms, or it can be lifelong and progressive. Complications from nephrotic syndrome depend on the underlying cause of nephrotic syndrome. Complications of untreated or poorly controlled nephrotic syndrome can be serious, even life threatening in some cases. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of nephrotic syndrome include:
Ascites (abdominal fluid accumulation)
Atherosclerosis (buildup of plaque on the walls of the coronary arteries; atherosclerosis is a type of arteriosclerosis)
Chronic infection (due to impaired immunity)
Renal vein thrombosis (blood clot in the veins draining blood from the kidneys)