What BUN/Creatinine ratio indicates dehydration?

A BUN/Creatinine ratio greater than 25:1 is indicative of dehydration, as this elevated ratio typically suggests that the kidneys are filtering out waste products less effectively due to reduced blood flow, which can happen in dehydrated states. When the body is dehydrated, the concentration of urea nitrogen in the blood increases relative to creatinine, leading to a higher ratio. This is because urea is disproportionately elevated when overall hydration is low, while creatinine levels tend to remain more stable in dehydration, resulting in a significant difference between the two measurements.

In contrast, a normal ratio, generally around 10:1, indicates proper kidney function with no signs of dehydration. Ratios less than 10:1 can suggest other issues, such as liver dysfunction or malnutrition. A ratio equal to 15:1 is also within the normal range and would not indicate dehydration. Understanding the significance of the BUN/Creatinine ratio is crucial for assessing hydration status and guiding appropriate interventions.