What is Urea?
Urea is a metabolic by-product of the process of conversion of protein into amino acids. Urea is formed in the liver and is transported by blood to the kidneys where it is excreted with urine. The Urea Test or Blood Urea Nitrogen (BUN) Test measures the levels of urea in the blood.
Why is Urea done?
The BUN Test is performed:
· As a part of metabolic panel tests for regular health checkups
· To check the functioning of the kidneys
· To diagnose kidney diseases
· To monitor efficacy of treatments for kidney diseases like dialysis
What does Urea Measure?
Urea is a by-product of protein metabolism. Proteins consumed in the diet are digested and converted into amino acids, which are utilized by the body. This metabolic process creates ammonia as a by-product. Ammonia is toxic and is thus rapidly converted by the liver to form the much less toxic compound urea that is transported relatively safely in blood. Urea formed in the liver is transported by the blood to the kidneys where it is filtered out of the blood and excreted out of the body in a solution called urine. The body continuously produces and excretes urea, hence a low and steady level of urea is continuously maintained in blood.
BUN levels in the blood are affected due to impairment of kidney function, or due to large-scale liver conditions. Primarily, BUN Test results are used to evaluate kidney functioning. Results are often interpreted together with results of Creatinine Test that measures the levels of another metabolic waste, creatinine, which is also excreted through urine.
Interpreting Urea results
Normal range (Approx.):
REFERENCE RANGE (mg/dL)
1 week to 1 year
Higher than normal BUN levels indicate impaired kidney function such that the kidneys are unable to effectively filter waste products out of the blood.
Lower than normal BUN levels are usually clinically insignificant. However, lower levels may be associated with large-scale liver conditions in some cases.
Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Urea
Frequently Asked Questions about Urea