Kimmelstiel-Wilson syndrome, also known as diabetic kidney disease, is a renal condition linked to prolonged diabetes. It primarily affects the microvasculature, which is the network of tiny blood vessels in the kidney's glomeruli. These glomeruli are essential for blood filtration. Characteristics of Kimmelstiel-Wilson syndrome include nephrotic syndrome, which results in excessive protein leakage into the urine (proteinuria), and gradually worsening kidney function. In severe cases, this syndrome can lead to kidney failure, necessitating either ongoing dialysis or a kidney transplant. The condition is named after Paul Kimmelstiel, a German-born physician who worked in the U.S., and Clifford Wilson, an English doctor. It is also referred to as Kimmelstiel-Wilson disease or intercapillary glomerulonephritis.