The offered Infinite BUN is used as a prognostic indicator for cardiovascular disease. We aimed to investigate the relationship between BUN levels and metabolic, biochemical, and histopathologic findings of nondiabetic patients. Blood urea nitrogen (BUN) is a serum byproduct of protein metabolism. It is one of the oldest prognostic biomarkers in heart failure. Infinite BUN is one of the oldest prognostic biomarkers in heart failure. Urea is formed by the liver and carried by the blood to the kidneys for excretion.