BUN

Blood Urea Nitrogen (BUN) measures the amount of nitrogen in the blood that comes from urea, a waste product formed in the liver from protein metabolism and excreted by the kidneys. Elevated BUN can indicate decreased kidney function, dehydration, high protein intake, or gastrointestinal bleeding. Low BUN is less common but can occur with liver disease or malnutrition. Often interpreted alongside creatinine (BUN/Creatinine ratio).