How you prepareBy Mayo Clinic staff
If your blood sample is being tested only for blood urea nitrogen, you can eat and drink normally before the test. If your blood sample will be used for additional tests, you may need to fast for a certain amount of time before the test. Your doctor will give you specific instructions.
- The kidneys and how they work. National Kidney and Urologic Diseases Information Clearinghouse. http://kidney.niddk.nih.gov/kudiseases/pubs/yourkidneys/. Accessed May 30, 2013.
- BUN. Lab Tests Online. http://labtestsonline.org/understanding/analytes/bun/tab/test. Accessed June 8, 2013.
- Taal MW, et al. Brenner & Rector's The Kidney. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-1-4160-6193-9..C2010-1-67932-1--TOP&isbn=978-1-4160-6193-9&uniqId=321553651-265. Accessed May 30, 2013.
- Inkler LA, et al. Assessment of kidney function. http://www.uptodate.com/home. Accessed May 30, 2013.
- Anderson CF (expert opinion). Mayo Clinic, Rochester, Minn. June 11, 2013.
- Castle EP (expert opinion). Mayo Clinic, Rochester, Minn. June 19, 2013.
- National Kidney Foundation. Tests to measure kidney function, damage and detect abnormalities. http://www.kidney.org/atoz/content/kidneytests.cfm. Accessed June 25, 2013.