AMK (Blood Urea Nitrogen) Test: Uses, Procedures, and Results


Blood urea nitrogen (BUN) is a blood test performed as a marker of kidney function. It is part of a basic or complete metabolic panel that is done to check your health. It is also used to monitor the progression of kidney failure.

AMK is formed when protein is broken down and is usually excreted from the blood by the kidneys. A value above normal may indicate kidney failure.

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What is blood urea nitrogen (BUN)?

AMK is a waste product of cellular metabolism. You get protein from the food you eat and it enters the bloodstream from the intestines for use by cells throughout the body.

Your cells break down proteins into amino acids to turn them back into proteins that they need for various processes. In this case, the nitrogen-containing ammonia is formed as a by-product, which enters the bloodstream.

The liver converts ammonia to urea to make it less toxic and sends the urea into the bloodstream. The kidneys filter urea from the blood.

If all goes well, a constant amount of urea is produced, which is excreted by the kidneys in the urine. Therefore, the level of AMK in the blood is stable. If the kidneys are damaged and not working properly, the urea and nitrogen it contains are not completely filtered from the blood.

Part of a test group

The BUN test is part of a typical Chem 7 blood chemistry test or a basic metabolic panel. This group of tests includes glucose, AMK, creatinine, carbon dioxide, sodium, potassium, and chloride. This panel is commonly used during health screenings and to monitor diabetes care. All tests are performed on the same tube of blood, usually analyzed in a laboratory using an instrument configured to perform all tests at the same time.

The purpose of the test

The purpose of the BUN test is to evaluate kidney function. It is also used to diagnose kidney disease and monitor the effectiveness of dialysis and other treatments associated with kidney disease or damage.

  • What the test measures: This test measures the amount of urea nitrogen in the blood. Urea is a waste product that is formed in the liver during protein metabolism. This process produces ammonia, which is then converted into less toxic residual urea.
  • High or low urea levels can indicate a problem: Diseases that affect the kidneys or liver can alter the amount of urea in the blood. The liver can make too much urea, or the kidneys cannot filter waste from the blood, which can lead to high levels of urea. High levels can be seen in people with gastrointestinal bleeding, high protein diets, infections and dehydration. Severe liver disease or damage can inhibit urea production, which can lead to a drop in the urea nitrogen concentration. Low levels of AMK can occur in people with liver failure, in pregnant women, and in those who are overhydrated.
  • Main Conditions: Diabetes and high blood pressure are two types of conditions that can affect the kidneys. Therefore, the BUN is preparing to monitor the health of the kidneys and the effectiveness of treatment in those already diagnosed with kidney disease.
  • Before special tests: BUN tests may be ordered before some imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI), which use contrast dyes that can damage the kidneys.
  • AMK is commonly used in conjunction with a creatinine test – The AMK test is primarily used in conjunction with a creatinine test to assess kidney function and monitor people with acute or chronic kidney dysfunction or failure . When ordered as part of a basic or comprehensive metabolic panel, it can be used to assess a person's overall health.
  • Limitations of the test: The AMK test is a quick way to assess kidney function, but there are some limitations. Small and large changes in BUN can occur due to medication intake, dietary changes, and hydration status. When AMK is outside the acceptable range, healthcare professionals often refer to a creatinine clearance test or AMK / creatinine ratio for a more accurate assessment.

Before the test

You do not need any special training to perform this test.

  • Time: This simple blood test takes a few minutes to complete. A blood sample is taken through a venipuncture.
  • Location: This test can be done in a laboratory, office, or healthcare facility.
  • Food and Drinks: In most cases, this test is included in the basic or complex medical commission before which people fast. You do not need to fast specifically for this test, but your healthcare provider may ask you to fast because of other laboratory tests included in the panel, such as fasting blood sugar (glucose control measurement).
  • Cost and medical insurance. The AMK test is generally covered by health insurance.

interpretation of results

  • The normal range for AMK is 6 to 20 mg / dL, although the range may vary slightly from laboratory to laboratory. Consult the range for your laboratory.
  • High urea nitrogen can be caused by impaired kidney function, congestive heart failure, urinary obstruction, shock, recent heart attack, dehydration, a high protein diet, or gastrointestinal bleeding.
  • Low levels of urea nitrogen are rare, but can be discovered incidentally with malnutrition, severe liver disease, or overhydration.

AMK in diabetes management

Kidney failure is a complication of diabetes. The level of AMK (blood urea nitrogen) in the blood is used to track the progression of kidney failure. AMK can also be controlled if you are given medications that can affect kidney function.

Get the word of drug information

The BUN test is a simple blood test used to measure kidney function. Your healthcare provider can order an AMK test for anyone, even if they don't have obvious symptoms or underlying conditions, and the result will be pretty quick.

If you get an abnormal result, the course of treatment will depend on the cause and its severity. For example, a higher level of urea nitrogen caused by dehydration indicates that a person needs to drink more fluids. The more serious consequences of abnormal AMK levels may lead to further testing or referral. Be sure to discuss your results with your doctor.

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