What is Urea - Spot Urine?

Also Known As: BUN (Blood Urea Nitrogen) Test

Formal Name: Urea Test

Urea is the final breakdown product of the amino acids found in proteins. Nitrogen in the form of ammonia is produced in the liver when protein is broken down. The nitrogen combines with other chemicals in the liver to form the waste product urea. The urea is released into the bloodstream and carried to the kidneys where it is filtered out of the blood and excreted in the urine. Healthy kidneys remove more than 90% of the urea the body produces, so blood levels can show how well your kidneys are working.

Most diseases that affect the kidneys or liver can affect the amount of urea present in the blood. If increased amounts of urea are produced by the liver or decreased amounts are removed by the kidneys then blood urea concentrations will rise. If significant liver damage or disease reduces the production of urea then urea concentrations may fall.

How is the sample collected for testing?

A blood sample is taken from a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is required.