How to Understand a Low BUN test

BUN tests are Simple Blood Tests

BUN (Blood Urea Nitrogen) tests are called to help give an idea how much kidney function that a patient has. It is included in two broad testing items that doctors and healthcare professionals can call for. They are the BMP (basic metabolic panel) and the CMP (comprehensive metabolic panel). Typically the BUN test will test for kidney function, tell the doctor if the patient's kidney treatment is working, or see how much the kidney function is worsening. It will test for nitrogen that is a byproduct of urea that is in the blood. It is sometimes given with a creatinine test as a number called the BUN to Creatinine ratio. Anyone over the age of 12 months should have a BUN to creatinine ratio result of 10:1 to 20:1.

Things You'll Need

• blood test

Instructions

1. The test is a simple blood test that involves nothing more than a vial of blood taken. There are very few side effects other than a tender needle site, perhaps some bruising. It is a very safe test that can signal how the kidneys are functioning in relieving the waste from the body. When liver or kidney function is strained it will show up as nitrogen in the blood.

   Low blood urea nitrogen results can be from different things. Some of the most logical reasons for the low BUN test are as follows:

2. • Gender - Women will have a lower BUN result than men.

3. • Liver Damage - Damage to the liver can show a low result.

4. • Age - Children have a lower BUN value than older folks.

5. • Overhydration - Too much water can make for a low test number.

6. • Malnutrition, Diet - Low protein diets can cause a lower than normal BUN test. To get a more normal BUN result, add the recommended amount of protein to the diet.

Tips & Warnings

• There are other reasons for a low BUN test result, and these are pregnancy, cancer, cirrhosis of the liver, muscle injuries, CNS (central nervous system) disease, and medications. Usually a low BUN test result is not a cause for any concern, but patients should be monitored in case it is from liver disease.

• Medications such as antibiotics, diuretics, and corticosteroids have all been shown to make the results of a BUN test appear low. In cases where the patient is on one of these medications an alternate test will need to be given, or the BUN test should be postponed until after the medication is flushed from the system.

Resources

• National Women's Health