If the liver produces urea in increased amounts or in case there is any problem in the functioning of the kidneys, there may be difficulty in filtering out the waste products from the blood, which will lead to a rise in urea concentrations in the blood. In the case of kidney or liver disease, there will be a change in the amount of urea present in the blood. This is a continuous process, a small amount of urea nitrogen always remains in the blood. Here, it is filtered out of the blood and then it is released into the urine. The liver releases urea into the blood, which is then carried to the kidneys. Usually, both ammonia and urea have nitrogen as the main component. It leads to the production of ammonia, which is further converted into urea. It is formed when the protein is metabolised into the amino acids.

This urea is a waste product that is formed in the liver. What does a Blood Urea Nitrogen (BUN) test measure?īlood Urea Nitrogen test analyses the amount of urea nitrogen in the blood. There is only one parameter: blood urea nitrogen. What are the test parameters included in the Blood Urea Nitrogen (BUN) test? The other names are Urea nitrogen test and serum BUN. What are the other names for the Blood Urea Nitrogen (BUN) test? And having too much urea nitrogen in the bloodstream can be a sign of kidney or liver problems. BUN levels tend to increase when the kidneys or liver are damaged or malfunctioning. Normally, the kidneys filter out the waste and urinating removes it from the body. Urea nitrogen is a waste product that is created by the liver when the body breaks down the proteins. It does so by analysing the amount of urea nitrogen in the blood. If kidney damage is a concern, ask your doctor what factors may be contributing to the damage and what steps you can take to try to control them.What is a Blood Urea Nitrogen (BUN) test?Ī blood urea nitrogen (BUN) test is used to evaluate how well your kidneys are functioning.

Certain medications, such as some antibiotics.

Congestive heart failure or recent heart attack.Dehydration, resulting from not drinking enough fluids or for other reasons.Generally, a high BUN level means your kidneys aren't working well. Infants have lower levels than other people do, and the range in children varies. Urea nitrogen levels tend to increase with age. In general, around 6 to 24 mg/dL (2.1 to 8.5 mmol/L) is considered normal.īut normal ranges may vary, depending on the reference range used by the lab and your age.

Results of the BUN test are measured in milligrams per deciliter (mg/dL) in the United States and in millimoles per liter (mmol/L) internationally. You can return to your usual activities immediately. The blood sample is sent to a lab for analysis. What you can expectĭuring the BUN test, a member of your health care team takes a sample of blood by inserting a needle into a vein in your arm. Your doctor will give you specific instructions. If your blood sample will be used for additional tests, you may need to fast for a certain amount of time before the test. If your blood sample is being tested only for BUN, you can eat and drink normally before the test. The GFR estimates the percentage of kidney function you have. To do this, you may have a blood sample taken to calculate your estimated glomerular filtration rate (GFR). Your doctor may also test how well your kidneys are removing waste from the blood. High levels of creatinine in your blood may be a sign of kidney damage. Creatinine is another waste product that healthy kidneys filter out of your body through urine. If kidney problems are the main concern, the creatinine levels in your blood will likely also be measured when your blood is tested for urea nitrogen levels. As part of a blood test group to help diagnose a number of other conditions, such as liver damage, urinary tract obstruction, congestive heart failure or gastrointestinal bleeding - although an abnormal BUN test result alone doesn't confirm any of these conditions.To help determine the effectiveness of dialysis treatment if you're receiving hemodialysis or peritoneal dialysis.If your kidney function needs to be evaluated, especially if you have a chronic condition such as diabetes or high blood pressure.If your doctor suspects that you have kidney disease or damage.

Normal ranges BUN