Which value represents the normal blood urea nitrogen (BUN) range?

Which value represents the normal blood urea nitrogen (BUN) range?

• A. 5-15 mg/dL
• B. 10-20 mg/dL
• C. 20-40 mg/dL
• D. 40-60 mg/dL

Answer: (B)

BUN values reflect how well the kidneys are excreting waste and how hydrated a person is. In adults, the usual reference range is about 7 to 20 mg/dL, and many exam resources use 10–20 mg/dL as a convenient standard normal interval. This makes sense because a value within roughly 10–20 mg/dL sits squarely inside the commonly accepted normal range for healthy individuals. Values above this range can point to issues like reduced kidney function, dehydration, high protein intake, or increased protein breakdown. Values below the range can occur with overhydration, liver disease, or malnutrition. Among the given options, 10–20 mg/dL best represents a typical normal BUN range, while 20–40 and 40–60 mg/dL would suggest elevated BUN and possible kidney or metabolic problems, and 5–15 mg/dL, while sometimes normal, does not align with the commonly used upper limit of normal.

BUN values reflect how well the kidneys are excreting waste and how hydrated a person is. In adults, the usual reference range is about 7 to 20 mg/dL, and many exam resources use 10–20 mg/dL as a convenient standard normal interval. This makes sense because a value within roughly 10–20 mg/dL sits squarely inside the commonly accepted normal range for healthy individuals.

Values above this range can point to issues like reduced kidney function, dehydration, high protein intake, or increased protein breakdown. Values below the range can occur with overhydration, liver disease, or malnutrition. Among the given options, 10–20 mg/dL best represents a typical normal BUN range, while 20–40 and 40–60 mg/dL would suggest elevated BUN and possible kidney or metabolic problems, and 5–15 mg/dL, while sometimes normal, does not align with the commonly used upper limit of normal.