Urea nitrogen urine testUrine urea nitrogen
Urine urea nitrogen is a test that measures the amount of urea in the urine. Urea nitrogen is a waste product resulting from the breakdown of protein in the body.
A 24-hour urine sample is 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 patients. 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.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
Low levels usually indicate:
- Kidney problems
- Malnutrition (inadequate protein in diet)
High levels usually indicate:
- Increased protein breakdown in the body
- Too much protein intake
There are no risks with this test.
Gerber GS, Brendler CB. Evaluation of the urologic patient: history, physical examination, and urinalysis. In: Wein AJ, Kavoussi LR, Novick AC, et al., eds. Campbell-Walsh Urology. 10th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 3.
McPherson RA, Ben-Ezra J. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 28.
Review Date: 8/25/2013
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, Bethanne Black, and the A.D.A.M. Editorial team.