Understanding BUN Blood Test

Tap to Read ➤ Ningthoujam Sandhyarani

A blood urea nitrogen (BUN) test is conducted as a diagnostic approach to examine renal function and competence. A high BUN test result signifies kidney dysfunction, and further tests are required for ruling out probable health complications.

In the normal digestion process, urea is generated as a waste product after the 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. Also, the level gradually increases with age. Testing the amount of urea in the blood is a simple way to examine the renal function. Scroll down for more information on the test results and interpretation.

What is a BUN Blood Test?

The BUN test involves the 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 fasting related to the test is concerned, it is not mandatory.

In fact, there is no specific preparatory step as such. But, the doctor may suggest a low intake of high-protein foods (like meat) 24 hours prior to the test. To get authentic test results, the person should cooperate with the health specialist by following his/her suggestions.

Why is the Test 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). It helps in ruling out symptoms that mimic kidney diseases. This 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 seeking medical attention and going for a BUN test.

For patients diagnosed with kidney diseases, a BUN 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, the blood urea test is conducted in association with the creatinine test to examine the metabolic performance of the kidneys. In such a case, a BUN-to-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 the urea from the blood, resulting in abnormal blood urea nitrogen levels.

Elevated amount of BUN is a cause of medical concern while reduced levels occur rarely and is not used as a reliable tool for medical diagnosis.

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 a slight fluctuation in the normal test range. Readings that are too low or too high should not be taken lightly.

Low Level A low BUN level may result due to excess fluids in the body (over hydration), nutrient deficiency, low-protein diet (especially amongst pure vegetarians), serious muscle damage, and life-threatening liver complications (at times). Nevertheless, this particular blood test is not used for screening any of these health conditions.

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

For pregnant women, it is quite normal to have any of the two readings, either low or high blood urea nitrogen. And a normal reading is expected even for those people who have a single, fully functional kidney.

Disclaimer : This story is for informative purposes only and should not be used as a replacement for expert medical advice.