What Is BUN Test?

July 22, 2019

The BUN test has nothing to do with soft pastries with sweet icing. If you have kidney problems it’s important to know what is BUN.  This acronym stands for Blood Urea Nitrogen (BUN). Research shows that about 850 million people around the world have kidney disease. It’s become a major problem in several countries. This is greatly due to factors like bad diet, lack of exercise, and stress levels. The kidneys are actually quite efficient and some people live with one from birth or after donating a kidney. However, modern life and factors like age and genetics can increase your risk of kidney disease. It’s important to get screened as soon as possible.

The BUN test is one of the most effective methods for detecting things like chronic kidney disease (CKD). It measures how much of the urea nitrogen is getting removed from your blood. The waste product is made in the liver then kidneys are supposed to filter it out from the blood so it doesn’t get stuck in the body. The problem is when the kidneys are damaged then they’re unable to remove this stuff from the bean-shaped organs. The BUN test results can help doctors to figure out if you have conditions like liver damage or other serious conditions.


What Is the Kidney?

The kidneys are shaped like–well, kidney beans and each of them is about the size of a human fist. The kidneys are located a little under the rib cage. There’s one kidney on each side of a person’s spinal cord.

When we have healthy kidneys, every minute they’re able to filter around 0.5 cups of blood. The process involves removing wastes and surplus water in order to form urine.

Then the urine moves from the kidneys to the person’s bladder via two rubes on either side of the bladder.  The kidneys are part of the urinary tract, which also includes other things like the bladder.

Kidneys are important since they remove stuff like waste and acid made from the body’s cells. This helps to maintain a healthy balance of stuff like salts, minerals, and water in the blood. They include the minerals sodium, potassium, and calcium.

This is a critical process because it helps the body to work normally. That includes things like nerves, tissues, and muscles.

The kidneys also make different kinds of hormones. These affect things like red blood cells, blood pressure, and bone strength.

Here’s how the system works. Blood first flows through the kidney. A big blood vessel then moves into small blood vessels until they get to a place where super-small blood vessels filter the blood. The blood then flows out of the kidneys.

Fun Fact: In one day a kidney filters around 150 quarts (142 milliliters) of blood. Most of the substances are returned to the blood and only 1-2 quarts become urine.

The problem is sometimes the kidneys don’t work properly. This can result in different health conditions like kidney disease. That’s why certain tests like BUN are critical to detect these conditions as soon as possible. The person can then get needed treatment.


What Is BUN?

That brings us to the BUN test. This is one of the various tests that can help doctors to check whether or not the kidneys are working properly. The test is used to measure waste in the blood known as “urea nitrogen.”

The liver makes this stuff after breaking down proteins. In normal cases the kidneys are able to filter out the waste then they’re removed from the body through urination.  When the kidneys and/or liver get damaged one of the signs is high BUN test levels.

This test is a basic blood test that’s used quite frequently. Sometimes it’s done with other tests like one known as the creatinine blood test. This provides doctors with more info so they check the results from both and determine what’s wrong.

These tests are often run in certain situations. They include doctor’s checkups, hospital stays, and post-treatments for diabetes and other health conditions.

This is a basic test and you won’t have to do any preparation before the exam. However, it’s important to inform your doctor of any over-the-counter (OTC) and pharmaceutical medicines you’re currently taking.

That’s because it can affect your body’s BUN levels. Some meds increase them and others lower them so it’s critical to find out if your doctor should factor in these meds when reading BUN results.

The test is very basic and just involves taking a small blood sample from you. The blood is drawn from arm veins.

A needle is inserted into the vein then the blood goes into a small tube that’s connected to the needle. You might experience a little pain but it won’t’ last long. A bandage is then applied.

There can be various causes of high BUN test results including liver damage. Some other possible causes include:

  1. Dehydration
  2. Malnutrition
  3. Bad circulation
  4. Urinary tract problems
  5. Heart failure


Reading BUN Results

There usually aren’t any side-effects from the test. If you feel weak or dizzy after the test you should inform your doctor immediately.

What do the BUN test results mean? They’ll be in milligrams per deciliter or mg/dL. “Normal” values are based on one’s age and gender. It’s also critical that “normal” figures are also based on what the lab defines as normal. So, this figure can differ from one lab to another one.

Here are some basic “normal” ranges:

  1. Adult men: 8-24 mg/dL
  2. Adult women: 6-21 mg/dL
  3. Kids 1-17 years old: 7-20 mg/dL
  4. Adults who are 60+ years old will usually have a slightly higher average than people in the under-60 age group.

If you have high BUN levels this can be signs of conditions like:

  1. Heart disease/failure
  2. Heart attack (recent)
  3. Dehydration
  4. High stress
  5. Urinary tract problems
  6. High protein levels
  7. Shock
  8. Kidney disease
  9. GI bleeding

Another possible cause of high BUN levels if some kinds of antibiotics.

Meanwhile, if you have low BUN levels here are some of the top causes:

  1. Malnutrition
  2. Liver failure
  3. Low protein levels

It’s important to take the test results in context. Your doctor might run 1+ tests to determine whether or not you indeed have a certain health condition.

A high/low BUN level doesn’t mean that you definitely have a kidney problem. There are various factors that can affect these levels. They include protein intake, hydration, steroids, aging, and pregnancy.

There are certain steps to boost or decrease your BUN levels. For example, you can decrease them with a low-protein diet, water, and meds.

Finally, after taking the BUN test you often won’t need to take any other tests. However, it depends on your situation. If you have a certain disorder then you might need to take other tests and possibly start new meds after learning what is BUN.