{"id":"bun","name":"Blood Urea Nitrogen (BUN)","shortName":"BUN","aliases":["BUN","Urea Nitrogen","Blood Urea Nitrogen","Urea Nitrogen, Serum","UREA N","BUN, Serum","Nitrógeno Ureico","Nitrógeno Ureico en Sangre","BUN (Nitrógeno Ureico)","Urea Nitrogen (BUN)","Blood Urea Nitrogen (BUN), Serum","Urea Nitrogen, Blood","Urea Nitrogen, Plasma","Urea Nitrogen, Serum or Plasma","Serum Urea Nitrogen","BUN Level","BUN (Blood Urea Nitrogen)"],"abbreviations":["BUN","UREA N"],"loinc":[{"code":"3094-0","primary":true},{"code":"14937-7","primary":false},{"code":"6299-2","primary":false},{"code":"59570-2","primary":false},{"code":"35234-4","primary":false}],"specimen":"serum-or-plasma","units":[{"ucum":"mg/dL","display":"mg/dL"},{"ucum":"mmol/L","display":"mmol/L"}],"referenceRanges":[{"population":"Men, 18+","low":8,"high":24,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Mayo Clinic Laboratories interval for men 18 and older. Labcorp prints 6–20 mg/dL for ages 18–39 (both sexes) in its pediatric reference document, and its sample report for a 62-year-old man shows 8–27 mg/dL. BUN tends to rise with age and intervals differ between labs, so the range printed on your own report is the best guide.","sources":[{"title":"Blood Urea Nitrogen (BUN), Serum (test ID BUN)","url":"https://schnecklab.testcatalog.org/show/BUN","publisher":"Mayo Clinic Laboratories (test catalog copy hosted by Schneck Medical Center)"},{"title":"Pediatric Testing Reference Ranges","url":"https://www.labcorp.com/content/dam/labcorp/drupal/178250_DX_TL_PediatricTestRef_Final.pdf","publisher":"Labcorp","year":2022},{"title":"Comp. Metabolic Panel (14), sample report (test 322000)","url":"https://files.labcorp.com/testmenu-d8/sample_reports/322000.pdf","publisher":"Labcorp","year":2022}]},{"population":"Women, 18+","low":6,"high":21,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Mayo Clinic Laboratories interval for women 18 and older. Labcorp's sample report for a 35-year-old woman shows 6–20 mg/dL.","sources":[{"title":"Blood Urea Nitrogen (BUN), Serum (test ID BUN)","url":"https://schnecklab.testcatalog.org/show/BUN","publisher":"Mayo Clinic Laboratories (test catalog copy hosted by Schneck Medical Center)"},{"title":"Basic Metabolic Panel (8), sample report (test 322758)","url":"https://files.labcorp.com/testmenu-d8/sample_reports/322758.pdf","publisher":"Labcorp","year":2022}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"BUN is a waste product from protein breakdown that your kidneys clear from the blood, so it gives a rough read on kidney function and hydration.","url":"https://bloodtesttracker.com/markers/bun","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}