A blood test measuring the amount of nitrogen in urea, a waste product of protein metabolism filtered by the kidneys. Elevated BUN levels suggest kidney dysfunction or dehydration.
The term combines 'blood' with 'urea' (from Greek 'ouron' meaning 'urine') and 'nitrogen' (from Greek 'nitron' meaning 'soda' and 'genes' meaning 'forming'). BUN became a standard kidney function test in the early 20th century.
Try Another Word