Description

The BUN/Creatinine Ratio measures the relationship between two key markers of kidney function:

  • BUN (Blood Urea Nitrogen): A waste product formed from protein metabolism in the liver and excreted by the kidneys.
  • Creatinine: A waste product produced by muscle metabolism and filtered by the kidneys.

Purpose:

  • Helps assess kidney function and overall kidney health.
  • Can indicate causes of kidney dysfunction, such as dehydration, kidney disease, or obstruction of urinary flow.
  • Helps distinguish between different types of kidney problems when evaluated with BUN and creatinine individually.

Why a Doctor May Order It Before a CT Scan:

  • Some CT scans require iodine-based contrast dye, which is processed and cleared by the kidneys.
  • The BUN/Creatinine ratio, along with individual BUN and creatinine levels, helps determine if the kidneys can safely handle the contrast dye.
  • Identifying impaired kidney function beforehand reduces the risk of contrast-induced kidney injury.

What the Results Mean:

  • High ratio: May suggest dehydration, high protein intake, or reduced blood flow to the kidneys.
  • Low ratio: May indicate liver disease, malnutrition, or certain kidney conditions.

Fasting: Not required.