Blood Urea Nitrogen (BUN) is an important indication of kidney function, so many patients care about whether their blood urea nitrogen level is high than the normal range. Then what is the dangerous level of BUN?
What is the normal range of BUN level?
For healthy individuals, it is 7-20 mg/dL in adults, and 5-18 mg/dL in children
Why BUN level elevates?
Blood carries protein to cells throughout the body. After the cells use the protein, the remaining waste product is returned to the blood as urea nitrogen. Healthy kidneys take urea nitrogen out of the blood and remove it in the urine. If your kidneys are not working well, the urea nitrogen will stay in the blood. As a result, the blood urea nitrogen level becomes abnormally high.
When the BUN level is considered dangerous?
If your creatinine level is higher than 20 mg/dL, your kidneys may not be working at full strength. However, to judge whether certain BUN level is dangerous depends on many factors. Compared with BUN, creatinine is a better indicator of kidney function. If your creatinine level remains stable but BUN level increases, this could be due to dehydration, a large amount of protein intake or intestinal tract bleeding. In that case, it is not so dangerous if you take immediate measures.
Therefore, a BUN test is better to be done with a creatinine test. If so, you will get the result— the BUN to Creatinine ratio. It is more accurate to judge how well your kidneys are functioning.
The normal BUN to Creatinine ratio for anyone over 12 months of age is a 10:1 to 20:1. They are designed to show the levels of kidney dysfunction the patient has. It can also be used as a measuring device to see if a kidney disease treatment is working or if the illness condition is worsening.