BUN and creatinine levels may increase in:

BUN and creatinine levels may increase in:

• A. Dehydration (BUN ONLY)
• B. Liver disease
• C. Renal Failure
• D. Excess protein intake

Answer: (C)

Both BUN and creatinine rise when kidney filtration declines. In renal failure, the kidneys can’t clear these wastes effectively, so their blood levels increase together. Creatinine comes from muscle metabolism at a fairly constant rate and is a more specific indicator of glomerular filtration, while BUN is influenced by hydration, protein intake, and liver function. Dehydration can raise BUN due to reduced kidney perfusion but often leaves creatinine normal or only mildly elevated. Liver disease can lower BUN production, so BUN isn’t high. Excess protein increases BUN but doesn’t affect creatinine the same way. So, only renal failure commonly causes both markers to rise.

Both BUN and creatinine rise when kidney filtration declines. In renal failure, the kidneys can’t clear these wastes effectively, so their blood levels increase together. Creatinine comes from muscle metabolism at a fairly constant rate and is a more specific indicator of glomerular filtration, while BUN is influenced by hydration, protein intake, and liver function. Dehydration can raise BUN due to reduced kidney perfusion but often leaves creatinine normal or only mildly elevated. Liver disease can lower BUN production, so BUN isn’t high. Excess protein increases BUN but doesn’t affect creatinine the same way. So, only renal failure commonly causes both markers to rise.