What is nephrotic syndrome?

Nephrotic syndrome is a kidney disorder that occurs when the filtering units of the kidneys become damaged which causes the body to excrete too much protein in the urine. The kidneys have groups of small blood vessels that filter waste and excess water from the blood. When these become damaged, it can lead to nephrotic syndrome. The condition can result in edema (swelling) which usually occurs in the ankles and feet. It also raises the risk of developing other health conditions such as infections and blood clots. 


Nephrotic syndrome causes signs and symptoms including significant edema, or swelling, which usually occurs in the ankles and feet and around the eyes, urine that looks foamy urine, which may be caused by excess protein in your urine, and weight gain which is a result of excess fluid retention. 

People develop nephrotic syndrome when the clusters of tiny blood vessels, or glomeruli, of their kidneys become damaged. Those clusters or blood vessels, aka glomeruli, work by filteringthe blood as it passes through the kidneys. This separates the substances that the body needs from the substances it does not need. The kidneys require healthy glomeruli keep blood protein, such as albumin, in order to keep the necessary amount of fluid in in the body and from flowing into the urine. When the glomeruli become damaged, too much blood protein is excreted from the body. This results in nephrotic syndrome.

Because nephrotic syndrome is not a specific kidney disease, is can occur as a result of a number of various kidney diseases which cause the filtering units to become damaged in a way that allows blood protein to leak into the urine. Some of the diseases and conditions that 

Many diseases and conditions can cause glomerular damage and lead to nephrotic syndrome, including:

• Diabetic kidney disease. Diabetes can cause kidney damage (aka diabetic nephropathy) which affects the glomeruli of the kidneys. 

• Blood clot in a kidney vein. Renal vein thrombosis, which occurs when a blood clot blocks a vein connected to the kidney, can cause nephroticsyndrome.

• Systemic lupus erythematosus. Systemic lupus erythematosus is a chronic inflammatory disease that can result in severe kidney damage. 

• Minimal change disease. Minimal change disease is the most common cause of nephrotic syndrome in children. It causes abnormal kidney function. However, when the kidney tissue is being looked at microscopically, it looks normal or close to normal. Therefore, it can be difficult to identify what the cause of the abnormal function is. 

• Focal segmental glomerulosclerosis. This condition occurs when some of the glomeruli become scarred. The scars are usually scattered along the glomeruli. Focal segmental glomerulosclerosis may be caused by another disease or a genetic defect. Sometimes, it is unclear what causes the condition. 

• Amyloidosis. Amyloidosis is a disorder that occurs when substances called amyloid proteins accumulate in the organs. When this happens, it can damage the filtering units or the kidneys. 

• Heart failure. Certain types of heart failure, such as constrictive pericarditis and severe right heart failure, can cause nephrotic syndrome.


• Membranous nephropathy. Membranous nephropathyis a kidney disorder which occurs when the glomeruli membranes become thick. It is unclear exactly what causes this to happen. However, it may be linked to underlying health problems such as cancer, lupus, hepatitis B, or malaria. 

There are a few risk factors that can increase your risk for developing nephrotic syndrome. Risk factor include:

• Medical conditions that cause kidney damage. For example, diabetes, lupus, amyloidosis, minimal change disease and other kidney diseases can increase your risk of developing nephrotic syndrome.

• Certain infections. Infections such as HIV, hepatitis B, hepatitis C and malaria increase your risk for developing nephrotic syndrome. 

• Certain medications. Medications like nonsteroidal anti-inflammatory drugs or drugs used to fight infections can increase your risk for developing nephrotic syndrome. 

In order to treat nephrotic syndrome, you must treat the underlying condition that is causing the condition. This may involve taking certain medications or changing your dietary habits. These methods are recommended as a way to reduce symptoms of or prevent whichever underlying condition is causing nephrotic syndrome. These treatment methods can also work to prevent any complications associated with nephrotic syndrome such as blood clots, high blood cholesterol and elevated blood triglycerides, poor nutrition, high blood pressure, acute kidney failure, chronic kidney disease, or infections.