Urine urea nitrogen is a test that measures the amount of urea in the urine. Urea is a waste product resulting from the breakdown of protein in the body.
A 24-hour urine sample is often needed. You will need to collect your urine over 24 hours. Your health care provider will tell you how to do this. Follow instructions exactly to ensure accurate results.
No special preparation is needed.
The test involves only normal urination. There is no discomfort.
This test is mainly used to check a person's protein balance and the amount of food protein needed by severely ill people. It is also used to determine how much protein a person takes in.
Urea is excreted by the kidneys. The test measures the amount of urea the kidneys excrete. The result can show how well the kidneys are working.
Normal values range from 12 to 20 grams per 24 hours (428.4 to 714 mmol/day).
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
Low levels usually indicate:
High levels usually indicate:
There are no risks with this test.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.