###Human: My BUN and creatinine ratio is 20. Is it high? ###Assistant: Hello. Normal BUN (blood urea and nitrogen) to creatinine ratio is anywhere between the range of 10:1 to 20:1. So your values are within the upper normal limits. The causes may be anything ranging from dehydration or lowered blood supply to kidneys due to any reason like heart disease. In this situation, I would recommend taking more and more fluids and go for another test to see the ratio after two weeks. We would see how it responds and if there is a need to do something else. You should also consult your local physician for the same. For more information consult an internal medicine physician online -->