Most Americans have heard of diabetes, heart disease, and even chronic kidney disease. But ask someone about FSGS, and chances are they will have no idea what it means.

That is a problem, according to kidney health experts.

FSGS, short for focal segmental glomerulosclerosis, is a rare but serious kidney disease that can lead to kidney failure. Despite its long name and growing impact, the condition remains largely unknown outside of nephrology clinics and patient support groups.

The disease causes scarring in the tiny filters inside the kidneys called glomeruli. Those filters remove waste and extra fluid from the blood. When they become damaged, protein can leak into the urine, and the kidneys gradually lose their ability to function.

Many people do not realize they have FSGS until the disease has already caused significant damage.

According to the National Kidney Foundation, common symptoms include swelling in the legs, ankles, or around the eyes, foamy urine caused by excess protein, fatigue, and high blood pressure. Some patients have no symptoms at all in the early stages.

A Hidden Threat in Kidney Health

The disease is drawing increasing attention because it affects Black Americans at disproportionately high rates.

Research published by Nationwide Children’s Hospital found that FSGS occurs at a rate of about 24 cases per million among African Americans, compared with about 5 cases per million among European Americans in the United States.

Scientists say part of that disparity may be linked to variants in a gene known as APOL1. The gene evolved thousands of years ago in parts of West and Central Africa, where it helped protect against a deadly form of sleeping sickness. While that genetic adaptation provided an advantage against infection, researchers now know it can also increase the risk of several kidney diseases, including FSGS.

The National Kidney Foundation reports that people with two APOL1 risk variants have a significantly higher chance of developing kidney disease. The variants are found most often among people with African ancestry, including many Black Americans, Afro-Caribbean populations, and some Latino communities.

Researchers estimate that about 13% of Black Americans carry two high-risk APOL1 variants. Yet many have never heard of the gene or its connection to kidney disease.

That lack of awareness can have serious consequences.

Kidney disease often progresses quietly. By the time symptoms become severe, patients may already be facing dialysis or the possibility of a kidney transplant.

Recent research published in The American Journal of Managed Care found that FSGS prevalence is highest among Black individuals and that healthcare costs rise sharply as kidney function declines. The study also found that patients with more severe disease require significantly greater medical care.

Advocates say these findings highlight the need for earlier screening, better education, and greater access to kidney specialists in underserved communities.

There is also growing interest in genetic testing and targeted treatments. New research is helping scientists better understand how APOL1-related kidney disease develops and how future therapies may slow or prevent damage. Several studies are exploring treatments designed specifically for patients whose disease is linked to APOL1 risk variants.

For many families, however, the biggest challenge remains awareness.

Kidney disease rarely receives the same public attention as cancer, heart disease, or diabetes. As a result, conditions like FSGS often remain invisible until someone they know receives a diagnosis.

Health advocates say that needs to change. Black Americans already face higher rates of kidney failure and are more likely to experience barriers to specialty care. Increasing public understanding of FSGS could help more people recognize symptoms, seek testing earlier, and access treatment before permanent damage occurs.

The next time someone asks, “What the heck is FSGS?” the answer may be more important than they realize. For thousands of families living with the disease, greater awareness could be the first step toward earlier diagnosis, better treatment, and healthier futures.