Focal segmental glomerulosclerosis, commonly known as FSGS, is a serious kidney disease that affects many people worldwide. The disease damages the glomeruli, which are tiny filters in the kidneys that help eliminate waste and excess water from the bloodstream. There are a few synonyms for FSGS, including primary FSGS, idiopathic FSGS, and focal glomerulosclerosis. The term "primary" refers to the fact that the cause of the disease is unknown, while "idiopathic" means that the condition has no apparent cause. Additionally, "focal" describes the pattern of scarring in the kidneys, while "glomerulosclerosis" refers to the hardening and scarring of the glomeruli. These synonyms help medical professionals to accurately diagnose and treat FSGS patients.