What is the normal BUN range?

What is the normal BUN range?

• A. 8-12
• B. 10-20
• C. 12-22
• D. 15-25

Answer: (B)

BUN shows how much nitrogen is in the blood from urea, a waste product of protein breakdown that the liver makes and the kidneys excrete. A typical adult normal range is about 7–20 mg/dL, though some labs and references use 8–20 mg/dL. In many nursing resources, 10–20 mg/dL is the commonly cited normal span, so this range best matches standard expectations. Thus, 10–20 mg/dL is the best choice because it aligns with the common reference used in clinical practice. The other ranges are either too narrow or extend the upper limit beyond what’s typically considered normal, which would misclassify normal values. Remember, BUN values can be influenced by hydration, protein intake, and kidney function, and should be interpreted alongside creatinine and the overall clinical picture.

BUN shows how much nitrogen is in the blood from urea, a waste product of protein breakdown that the liver makes and the kidneys excrete. A typical adult normal range is about 7–20 mg/dL, though some labs and references use 8–20 mg/dL. In many nursing resources, 10–20 mg/dL is the commonly cited normal span, so this range best matches standard expectations.

Thus, 10–20 mg/dL is the best choice because it aligns with the common reference used in clinical practice. The other ranges are either too narrow or extend the upper limit beyond what’s typically considered normal, which would misclassify normal values. Remember, BUN values can be influenced by hydration, protein intake, and kidney function, and should be interpreted alongside creatinine and the overall clinical picture.