A BUN creatinine ratio less than 20 suggests which type of condition?

A BUN (Blood Urea Nitrogen) to creatinine ratio of less than 20 typically suggests renal problems. In the context of kidney function assessment, the ratio is used to help differentiate between various types of acute kidney injury.

When the kidneys are functioning normally, both BUN and creatinine levels can be elevated in certain conditions; however, in renal conditions such as glomerulonephritis or acute tubular necrosis, the BUN level might not increase as much as creatinine. This results in a lower BUN to creatinine ratio, indicating that the rise in creatinine is more significant compared to BUN.

In essence, a BUN to creatinine ratio below 20 points to intrinsic renal issues, where the kidneys themselves have a direct impairment. This understanding is crucial in the evaluation of renal function and guiding further diagnostic and therapeutic approaches.