 [ Symptoms ] a free blood screening = bun of 21 my creatinine serum was 0 93 and my buncreatinine ratio was 23 do i call dr [ Disease ] well let is start at the beginning i will include some links to more information the bun blood urea nitrogen test basically is used to give an idea of how well your kidneys are working a normal bun range for adults is around 6 20 mgdl the fact your bun is 21 is not necessarily reason for concern many factors including various medications can affect the bun result and 21 might even be normal for you it is hard to say without some past lab results to compare with serum creatinine ranges in adult men run from about 0 6 1 2 mgdl and for women the range is around 0 4 1 0 so it sounds like your creatinine level is within normal limits a normal buncreatinine ratio is considered to be 101 201 your buncreatinine ratio is slightly elevated but probably no cause for alarm however your best bet is always to consult a health care provider to discuss these results what is normal for one person may not be normal for another that is why we health professionals recommend you get blood work done every year by comparing past results with current ones we can get a better idea of whether you have a problem developing that needs treatment since i have no background information on you specifically it is impossible to say if these results deserve further investigation if you are at all concerned about them you should visit your primary care provider best wishes to you no