BUN (Blood Urea Nitrogen)

What is Blood Urea Nitrogen (BUN)?

Blood urea nitrogen (BUN) is a test of kidney function to measure the amount of urea nitrogen present in the blood. Urea is a waste product that results from the breakdown of protein in food. Urea is created in the liver and is removed from the body by the kidneys. It is measured in milligrams of urea nitrogen per deciliter (mg/dL).

Preparation for BUN Test

No special preparation is usually needed for a blood urea nitrogen test. Your doctor might ask you to avoid certain medications, such as diuretics, for a day or two before having the test.

Procedure for BUN Test

The BUN test is a simple blood test. A healthcare professional will take a small sample of blood, which will typically be sent to a laboratory for testing.

Types of BUN Tests

There are two types of BUN tests. The first is a standard BUN test which measures the urea nitrogen in the blood; this is the most common type of test used. The second type is known as a fractional BUN test. This test measures the concentration of urea nitrogen in the urine. This test is usually used to diagnose conditions such as urinary tract infection, kidney disease, and liver cirrhosis.

Risks of BUN Test

The BUN test is a very simple test with minimal risk. Most people experience no discomfort or pain. The risk of infection or bleeding is also very low. However, in rare cases, complications such as bleeding and bruising can occur.

Why is BUN Test Done?

The BUN test is done to assess kidney function and check for any problems or diseases associated with the kidneys, such as kidney failure. It can also be used to help diagnose the cause of high blood pressure, diarrhea, dehydration, and urinary tract infections.

When is BUN Test Ordered?

The BUN test is most commonly ordered when a doctor suspects that a person has an underlying kidney or liver condition. A BUN test may also be ordered when a person has symptoms of kidney or liver disease, such as high blood pressure, anemia, or confusion. Additionally, a BUN test can be ordered as part of a routine annual physical exam. It may also be ordered to determine if a person who has a chronic illness is responding to treatment.