Urine urea nitrogen
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.
Agarwal R. Approach to the patient with renal disease. In: Benjamin IJ, Griggs RC, Wing EJ, Fitz JG, eds. Andreoli and Carpenter's Cecil Essentials of Medicine. 9th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 26.
Riley RS, McPherson RA. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 29.BACK TO TOP
Review Date: 7/21/2021
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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