BUN Blood Test

In the normal digestion process, urea is generated as a waste product after breaking down of proteins. This urea produced in the liver is released in the bloodstream, which is then excreted in the urine via the kidneys. As compared to children and women, men have a relatively higher BUN (blood urea nitrogen). Also, the level increases gradually with age. Testing the amount of urea in the blood is a simple way to examine the renal function. And such a medical procedure is referred to as BUN blood test.

What is BUN Blood Test?

The blood urea nitrogen (BUN) test involves measurement of nitrogen concentration in the blood, which is present in the form of urea. Similar to any type of blood test, a blood sample is drawn from the vein, which is sent to a diagnostic laboratory for further testing. As far as BUN blood test fasting is concerned, it is not mandatory. In fact, there is no specific preparatory step as such. But, the doctor may suggest low intake of high protein foods (meat) within 24 hours prior to test. To get authentic test results, the candidate should cooperate with the health specialist by following his suggestions.

Why BUN Blood Test is Conducted?

The BUN test may be ordered to monitor a person's general health, as a part of comprehensive metabolic panel (CMP) or basic metabolic panel (BMP). BUN helps in ruling out symptoms that mimic kidney diseases. This blood test may also be performed to monitor renal function prior to starting long-term drug therapies. A notable sign of high urea levels in the bloodstream is a marked reduction in the urine output. If this condition is accompanied with suspected kidney disease symptoms, one should not delay in getting medical attention and going for BUN blood test.

For patients diagnosed with kidney diseases, BUN blood test is performed to see if the kidneys are improving or getting worse. The result helps in confirming whether a specific therapeutic treatment is working for the patient or not. Accordingly, the doctor will continue the therapy, or consider changing it with another approach. Generally, blood urea test is conducted in association with the creatinine test to examine the metabolic performance of the kidney organs. In such a case, the BUN creatinine ratio is determined for health objectives.

BUN Blood Test Results

For healthy people, the amount of blood urea reading is normal, while in an individual with renal failure or similar condition, the kidneys fail to remove urea from the blood, resulting in abnormal blood urea nitrogen levels. Elevated amount of BUN is a cause of medical concern, while reduced BUN level occurs rarely and is not used as a reliable tool for medical diagnosis. For better understanding, BUN blood test interpretation is explained below.

BUN Blood Test: Normal Range
The normal level of blood urea nitrogen for a healthy adult male falls between 8-24 mg/dL blood, while the normal range is 6-21 mg/dL for an adult female. However, according to the procedure conducted, there may be slight fluctuation in the normal BUN blood test range. Readings that are too low or too high should not be taken lightly.

BUN Blood Test: Low Level
Low BUN level may be resulted due to presence of excess fluid (over hydration), nutrient deficiency, low protein diet (especially amongst pure vegetarians), serious muscle damage and at times, life-threatening liver complications. Nevertheless, this particular blood test is not used for screening any of these health conditions.

BUN Blood Test: High Level
If the BUN blood test result shows an increased amount of nitrogen, it is medically referred to as azotemia. The reason for elevated BUN is attributed to the inability of the kidneys to filter urea properly. An indication for impaired kidney function, blood urea nitrogen also rises because of high protein diet, medicinal side effect, dehydration, heart failure, gastrointestinal bleeding, urinary tract blockage and Addison's disease.

So, this was a brief information about the BUN blood test. For pregnant women, it is quite normal to have any of the two readings, low blood urea nitrogen or high blood urea nitrogen. And normal reading is expected even for people who have a single fully functional kidney.