Dr. Richard Lafayette, founder and director of the Glomerular Disease Center at Stanford University Medical Center, discusses the prevalence and impact of IgA nephropathy, the most common primary glomerular disease worldwide. Highlighting the annual incidence and overall prevalence in the United States, he explains how the disease often presents with symptoms like swelling, fatigue, and blood in the urine, although it can also be asymptomatic, leading to late diagnosis. Treatment focuses on diet, weight management, and stringent blood pressure control with renin-angiotensin system inhibitors to protect kidney function.