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Low BUN Levels

Low BUN Levels

Blood Urea Nitrogen (BUN) levels are tested to verify the function of kidneys. This article will help you understand what low BUN levels indicate, along with a few measures to restore them to normal.
Charlie S
Last Updated: Mar 19, 2018
The Blood Urea Nitrogen test, which is also known as the Urea Nitrogen test or the Serum Urea Nitrogen test is conducted along with the Creatinine test. The use of these tests is to check if the kidneys of the patient are functioning normally.
The BUN test may be performed as a routine check-up or if the doctors suspect the patient's kidneys to be malfunctioning. It may be suggested to patients who are experiencing symptoms such as fatigue, swelling around the eyes, or high blood pressure, which point towards kidney disease.
BUN Test Procedure
Patients are advised not to consume any protein-rich meals, 24 hours prior to the test as it can interfere with the results. During the test, an elastic band is wrapped around the patient's arm, in order to make the vein prominent. An injection is then inserted into the vein to draw blood. The patient simply feels a slight prick, as is the case during a routine blood test. Once the sample is taken, a cotton pad is held on to the area and a bandage is applied.
Interpreting BUN Levels
Normal BUN Levels
  • Men: 8 - 24 mg/dL
  • Women: 6 - 21 mg/dL

Our liver performs the function of processing the protein that we consume through our meals. As a part of this process, the liver secretes waste in the form of urea, which then enters the blood stream. It is up to the kidneys to separate the urea from the blood and eliminate it through urine.
The purpose of getting BUN levels tested is to check if your kidneys are working fine. Therefore, when the test results show raised BUN levels, it means that your kidneys are failing to correctly eliminate waste from your body. A protein-rich diet, severe dehydration, or heart problems can be the cause of high BUN levels.
Low BUN levels, on the other hand, can be a result of liver disease or malnutrition. People who consume proteins in a very low proportion are also prone to this condition. Also, there are instances where this has been observed in those who are excessively hydrated.
Interestingly, women and children have been observed to process proteins in a different manner than men, which is the reason why their BUN levels are comparatively lower.
In some cases, low BUN levels have also been detected in the second or third trimester of pregnancy, the occurrence of which is not considered abnormal.
The prime cause is believed to be the intake of food which is very low in protein content. Malnourished people are often reported to suffer from this condition.

Regular consumption of a diet high in carbohydrates may also be a reason.

Liver disease is known to cause low BUN levels. Liver problems could be present at birth, or may later occur due to faulty metabolism, inadequate nutrition, alcoholism, infections, etc.

A malfunctioning pancreas can lower your BUN levels too.

Intake of anabolic steroids can also be responsible for this condition.
Looking at the causes, it would be safe to say that restoring them would require a lifestyle overhaul. If you are suffering from this condition, you must certainly visit your doctor, who would come up with the best possible solutions. Alternatively, you could also try to consume fresh and nutritious food on a regular basis to increase your protein intake. Secondly, you need to give up things that cause liver damage, be it alcohol or a hectic lifestyle. Your doctor may also prescribe medication to help you raise your BUN levels.
Note: This HealthHearty article is for informative purposes only, and should not be used as a replacement for expert medical advice.