Focal Segmental Glomerulosclerosis (FSGS) Explained


Jan 4, 2023

Focal Segmental Glomerulosclerosis (FSGS) Explained

What is FSGS?

Focal Segmental Glomerulosclerosis (FSGS) is a disease in which scar tissue develops in the parts of the kidney that filter waste from the blood.  These small parts are called the glomeruliDiseases that cause damage to the kidneys filtering system are called glomerular diseases, and they have many causes.  FSGS is a type of glomerular disease.

Each kidney has thousands of glomeruli, and “focal” means that only some of the glomeruli become scarred, while others remain normal.  “Segmental” means that only part of an individual glomerulus is damaged, and “sclerosis” means scarring.                                                           

FSGS is a serious condition that can lead to kidney failure, (also called end stage renal disease, or end stage kidney disease).   If that happens the person affected will need to receive a kidney transplant or begin dialysis treatments in order to sustain life.  

Focal Segmental Glomerulosclerosis affects both children and adults.  It affects men slightly more than women, and it occurs more frequently in African Americans.  

What causes FSGS?

FSGS is rare, with about 7 in every 1 million people diagnosed each year. Focal Segmental Glomerulosclerosis has many different causes, there is not one known cause.  The scarring to the kidneys can happen due to a drug or an infection. It can also be caused by a disease that affects the whole body, such as diabetes, HIV, lupus,  sickle cell disease, and by another glomerular disease. The following is a list of health problems that are thought to cause FSGS. Having one of these health problems does not mean you will develop FSGS. If you have any concerns about how your kidneys may be affected by an existing condition, please see your healthcare provider for further information on your particular circumstances.  

  • Diabetes
  • Sickle cell disease
  • Infections, including some viruses, such as HIV
  • Lupus
  • Being overweight
  • High blood pressure
  • Long term drug use of certain drugs.  (such as anabolic steroids and heroin).
  • Some medications (such as for treating cancer).
  • Problems since birth with kidneys (birth defect)
  • Too much urine in your kidneys

Is there more than one type of FSGS? 

There are different types of FSGS based upon what caused it. These are the types of FSGS:

  • Primary FSGS  This type of FSGS means that the disease occurred on its own without a known cause. 
  • Secondary FSGS  This type of FSGS is caused by another condition or by drug use.  
  • Genetic (also known as Familial) FSGS  This type of FSGS is inherited (passed down through your family).

What are the symptoms of FSGS?

You may not notice any symptoms, especially in the early stages of FSGS.  As it progresses, you may notice the following symptoms:

  • Swelling, called edema, especially in your legs and ankles, and around your eyes.  
  • Weight gain  this is due to the extra fluid buildup in your body.
  • Foamy urine  this is caused by high protein levels in the urine. 

Other symptoms can only be found by your healthcare provider through tests.   Those symptoms include:

  • Protein in the urine
  • Low level of protein in the blood.
  • Too much fat in your blood. (high cholesterol). 

How do you know if you have FSGS?

In order to know if you have FSGS you will need to have a kidney biopsy.  A kidney biopsy is a procedure done with a special needle. The needle is used to take a very small piece of the kidney so that it can be examined under a microscope.  

Your healthcare provider may also want to order the following tests:

  • Urine test.  This test is performed in order to see if there is protein and blood in the urine.
  • Blood tests.  This is to examine the levels of protein,  cholesterol, and waste in the blood. This will help to provide information about how well your kidneys are working.  
  • Genetic testing.  Genetic tests may also be done to see if you were born with a problem that has caused your kidney disease.  

Your healthcare provider will use all of the information from tests performed in order to plan a treatment that is best for you.  

How is FSGS treated?

Treatment for FSGS depends on what type of FSGS you have, and what caused you to develop FSGS.   Treatments for FSGS usually include the following:

  • Immunosuppressants .  Immunosuppressants are medications that can help to stop your body from attacking your kidneys.
  • Blood pressure medications.  This type of medicine helps to lower the amount of protein lost as well as helping to control your blood pressure. 
  • Diuretic medications.  These are also known as “water pills”, they help your kidneys to get rid of fluid and salt, making you urinate more. 

Your treatment plan should also include healthy life changes. These could include your diet, switching to a kidney friendly diet to help keep you healthy, and increasing your activity level to 30 minutes daily, or most days.  Stop any unhealthy habits you may have, such as smoking, any drugs, excessive alcohol use.  Talk with your healthcare provider if you think you may need help in this area so that you may quit successfully.

Related Article

What is Chronic Kidney Disease (CKD)?

What Do Your Kidneys Do?

Anatomy of the Kidney


Mayo Clinic

National Kidney Foundation

American Kidney Fund

About the Author

Monica Thomas

Monica McCarthy has bachelors in Political Science and Criminal Justice from Central Washington University.  A majority of her career was spent as a political consultant.   She currently works at KidneyLuv as a staff writer.

Patient Education Disclaimer

This material is for informational purposes only. It does not replace the advice or counsel of a doctor or health care professional. KidneyLuv makes every effort to provide information that is accurate and timely, but makes no guarantee in this regard. You should consult with, and rely only on the advice of, your physician or health care professional.

KidneyLuv Logo