What Is FSGS? 

FSGS is a kidney disease that causes scarring in the glomeruli, the tiny filtering units inside your kidneys. When those filters scar, they leak protein into the urine and slowly lose function. Over time this can lead to kidney failure.

FSGS affects both children and adults and is more common in Black and African American individuals. 

There are four types: 

• Primary: the immune system attacks the kidney's filtering cells

• Secondary: triggered by another condition like obesity, HIV, or certain medications

• Genetic: inherited or caused by a gene mutation

• Undetermined: no clear cause identified 

You may be at higher risk if you have:

• A family history of kidney disease

• High blood pressure, diabetes, obesity, or sickle cell disease

• HIV, COVID-19, or an autoimmune condition

• APOL1 gene variants (more common in people of African descent) 

Symptoms and Diagnosis 

FSGS often has no symptoms early on. As it progresses, you may notice:

• Foamy or bubbly urine: protein leaking from your kidneys

• Swelling in your legs, ankles, feet, or around your eyes

• Sudden weight gain from fluid buildup

• High blood pressure Fatigue or weakness 

How Is It Diagnosed? 

• Urine test: checks for protein, the earliest sign of kidney damage

• Blood test (eGFR): measures your kidney filtering rate 

• Genetic testing: the only way to know if you carry the APOL1 variants 

• Kidney biopsy: in some cases, recommended by your doctor

Treatment and Your Key Numbers 

Treatment depends on your type of FSGS but the goal is always the same, lower protein in your urine and keep it low.

• Primary FSGS: steroids or medications to reduce immunedriven inflammation

• Secondary FSGS: treat the underlying cause

• All types: blood pressure medications, low-salt diet, regular exercise, and routine monitoring 

Track These Three Numbers at Every Visit

• Proteinuria: the main driver of kidney damage.

• Partial remission goal: below 1.5 g/d

• Complete remission goal: below 0.3 g/d

• eGFR: kidney filtering function. Normal is 90 or above.

• Blood pressure: <120/80 mm Hg 

Living with FSGS and Next Steps 

Work closely with your care team, take your medications as prescribed, and watch for changes in swelling or weight. 

A New Treatment Is Here 

For the first time, there is an FDA-approved medication specifically for FSGS. FILSPARI® (sparsentan) was approved in April 2026 for adults and children aged 8 and older. It is a once-daily oral pill that works to reduce protein in the urine.

Your Next Steps 

1. If you notice foamy urine or unexplained swelling, talk to your doctor 

2. Ask for a urine protein and eGFR test at your next visit 

3. Ask your doctor if FILSPARI may be right for you 

4. Share what you learned with your family, FSGS can be genetic 

5. Stay connected at embarkawareness. org

Key Takeaway 

FSGS can be managed, especially when caught early. Stay informed, track your numbers, and keep showing up.