Nephrotic syndrome treatments, causes & symptoms
- Medically reviewed by
- AKF's Medical Advisory Committee
- Last updated
- December 5, 2022
Who is at risk for nephrotic syndrome?
Anyone can get nephrotic syndrome, but it is slightly more common in men than in women. In children, it happens most often between the ages of two and six. There are other factors that may increase your risk.
You are more likely to get nephrotic syndrome if you:
- Have a disease that affects the kidneys such as FSGS, lupus or diabetes
- Take certain medicines like nonsteroidal anti-inflammatory drugs (NSAIDS) or antibiotics
- Have an infection such as HIV, hepatitis B and C or malaria
What are the symptoms of nephrotic syndrome?
You may not know that you have nephrotic syndrome until you have routine blood and urine tests at a doctor's appointment. The results of your tests can show that you have too much protein in your urine, not enough protein in your blood, or too much fat or cholesterol in your blood.
Signs of nephrotic syndrome that you may notice are:
- Swelling in your legs, feet, ankles and sometimes face and hands
- Weight gain
- Feeling very tired
- Foamy or bubbly urine
- Not feeling hungry
What causes nephrotic syndrome?
Nephrotic syndrome happens when you have a disease that damages the filters in your kidneys causes them to not work as they should. There are primary and secondary causes of nephrotic syndrome.
Primary causes of nephrotic syndrome are diseases that affect only the kidneys.
The most common primary cause of nephrotic syndrome in adults is a disease called focal segmental glomerulosclerosis (FSGS). The only way to know for sure whether you have FSGS is to get a kidney biopsy. Even when treated, most people with FSGS will eventually develop kidney failure and will need to start dialysis or have a kidney transplant to live. After transplant, there is still a chance that FSGS will return and that you may lose your new kidney.
In children, the most common primary cause of nephrotic syndrome is minimal change disease.
Secondary causes of nephrotic syndrome are diseases that affect the whole body, including the kidneys.
Most of the time, nephrotic syndrome happens because of secondary causes. The most common secondary cause of nephrotic syndrome in adults is diabetes.
The most common secondary cause of nephrotic syndrome in children is diabetes.
What are the complications of nephrotic syndrome?
When you have nephrotic syndrome, an important protein called albumin leaks into your urine instead of getting filtered by the kidneys as it should. Albumin helps your body get rid of extra fluid. When you do not have enough albumin in your blood, fluid can build up in your body, causing swelling in your legs, feet and ankles. You can also have other problems such as blood clots and infections.
With nephrotic syndrome, cholesterol also builds up in your blood. When you have too much cholesterol in your blood, clumps form inside your veins and arteries, which can cause a heart attack or a stroke.
Nephrotic syndrome can also cause other serious health problems such as:
- Heart disease
- High blood pressure
- Fluid buildup
- Acute kidney injury
- End-stage renal disease (ESRD) or kidney failure
How do doctors test for nephrotic syndrome?
Healthy kidneys remove extra fluid and waste from your blood but let proteins and other important nutrients pass through and return to your blood stream. The only way to know how well your kidneys are working is to get tested. Tests doctors use for kidneys are:
- Urine tests. Your urine test results can tell your doctor if there is protein in your urine. If so, you may have nephrotic syndrome. Protein in the urine is one of the earliest signs of kidney disease.
- Blood tests. Your blood test results can tell your doctor if your kidneys are filtering waste like they should. If not, it could be a sign of nephrotic syndrome.
- Kidney biopsy. In a kidney biopsy, your doctor will look at a small piece of your kidneys under a microscope for signs of damage and disease.
To be sure you do not have a problem with your kidneys, you should have both a urine test and a blood test. Having a urine and a blood test is important because you could have normal blood test results but still have too much protein in your urine. Protein in your urine could mean you have kidney disease.
How is nephrotic syndrome treated?
There is no cure for nephrotic syndrome, but your doctor might tell you to take certain medicines to treat the symptoms and to keep the damage to your kidneys from getting worse. Talk with your doctor or a member of your dialysis care team about your medication options. They may prescribe:
- Medicine to control blood pressure and cholesterol which can help prevent you from having a heart attack or a stroke.
- Medicine to help your body get rid of extra water which can help control your blood pressure and can reduce swelling.
- An injection therapy that may reduce inflammation.
Is there a special diet for nephrotic syndrome?
Changing how you eat may also help you manage your symptoms. When you have nephrotic syndrome, a dietitian may recommend that you make changes to the amount of protein, salt and fat that you eat. Check out Kidney Kitchen to learn more about how these nutrients can affect your kidneys.
The amount of protein you should eat depends on how healthy your kidneys are. For some people with nephrotic syndrome, eating less protein is best. Talk to a dietitian about how much protein you should eat.
For more information on protein and how to manage it through the food you eat, watch our webinar on our Kidney Kitchen website. We also have a downloadable guide of many common foods and how much protein they have.
Limiting how much salt (sodium) you eat and drink can help prevent swelling and keep your blood pressure at a healthy level.
Watch our video to get tips on managing sodium.
Eating foods low in saturated fat and cholesterol can help prevent high cholesterol associated with nephrotic syndrome. Choosing fish or low-fat cuts of meat instead of cuts with high fat can help keep your cholesterol under control.
What if my kidneys fail?
If your kidneys stop working because of nephrotic syndrome, you will need dialysis or a kidney transplant to live. If you are interested in getting a transplant, you must have a full health evaluation by a transplant team at a transplant center. The evaluation will help the transplant team decide if you are ready for the kidney transplant. If the transplant team decides you are ready, the next step will be for your transplant team to help you find a kidney match.
How long will I have to wait for a transplant if I need one?
The process of getting listed for a kidney transplant often begins after you your evaluation. The average wait time for a kidney from a deceased donor is three to five years. If you have a donor who is willing and able to give you a kidney, you can have your transplant as soon as both you and your donor are ready. Learn more about the kidney transplant waiting list and what you can do while you wait.
Can I get nephrotic syndrome even after I have a transplant?
Yes, you can get nephrotic syndrome even after your transplant. Remember, nephrotic syndrome is not a single disease. It is caused by different diseases that affect your kidneys. If you get a kidney transplant but do not treat the disease that is affecting your kidneys, the disease may continue to harm your new kidney.
Questions to ask your doctor
If you find out you have nephrotic syndrome, talk with your doctor about the cause of your symptoms and what treatment is best for you. Here are some questions you may want to ask:
- What is causing my symptoms?
- Have you ruled out FSGS and other primary causes of nephrotic syndrome?
- What can I do to manage my symptoms?
- How much more time do I have until I will need to either get a transplant or go on dialysis?
- What are the chances that my nephrotic syndrome will return if I get a transplant?
- What can I do to avoid losing my new kidney to nephrotic syndrome after my transplant?
Where can I find more information on nephrotic syndrome?
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) has information about nephrotic syndrome in adults and nephrotic syndrome in children.