{"id":"anion-gap","name":"Anion Gap","shortName":"Anion Gap","aliases":["AG","Anion Gap, Calculated","Anion Gap (Na-Cl-HCO3)","Brecha aniónica","Anionenlücke","Serum Anion Gap","Anion Gap, Serum","Anion Gap, Plasma","Anion Gap (Calculated)","Anion gap, calc","Calculated Anion Gap","Plasma Anion Gap","Anion Gap 3"],"abbreviations":["AG","AnGAP"],"loinc":[{"code":"33037-3","primary":true},{"code":"10466-1","primary":false}],"specimen":"calculated","units":[{"ucum":"mmol/L","display":"mmol/L"},{"ucum":"meq/L","display":"mEq/L"}],"referenceRanges":[{"population":"7+","low":7,"high":15,"unit":"mmol/L","unitDisplay":"mmol/L","note":"Mayo Clinic Laboratories prints 7–15 for ages 7 and older, with no sex split, and has not established an interval for children under 7. Mayo's page shows no unit, but ARUP reports the anion gap in mmol/L, which is numerically the same as mEq/L, and lists the interval for its panels as 'by report' because it varies with the instrument. MedlinePlus and the Merck Manual also give no single range. The normal range depends on the analyzer and the formula, and it is wide (often 8–10 mEq/L across). Studies of healthy people report ranges from about 5–12 to 10–20 mEq/L depending on the analyzer (Kraut and Nagami 2013, Table 2), so use the range printed on your own report first. If your lab adds potassium to the formula, expect results and ranges to sit higher.","sources":[{"title":"Electrolyte Panel, Serum (test ID ELPSR)","url":"https://schnecklab.testcatalog.org/show/ELPSR","publisher":"Mayo Clinic Laboratories (catalog copy hosted by Schneck Medical Center)"},{"title":"Basic Metabolic Panel, Serum (test ID BMAMA)","url":"https://schnecklab.testcatalog.org/show/BMAMA","publisher":"Mayo Clinic Laboratories (catalog copy hosted by Schneck Medical Center)"},{"title":"Basic Metabolic Panel (test 0020399)","url":"https://ltd.aruplab.com/Tests/Pub/0020399","publisher":"ARUP Laboratories"},{"title":"The serum anion gap in the evaluation of acid-base disorders: what are its limitations and can its effectiveness be improved?","url":"https://pubmed.ncbi.nlm.nih.gov/23833313/","publisher":"Clinical Journal of the American Society of Nephrology","year":2013},{"title":"Metabolic Acidosis","url":"https://www.merckmanuals.com/professional/nephrology/acid-base-regulation-and-disorders/metabolic-acidosis","publisher":"Merck Manual Professional Version","year":2025},{"title":"Anion Gap Blood Test","url":"https://medlineplus.gov/lab-tests/anion-gap-blood-test/","publisher":"MedlinePlus (US National Library of Medicine)"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The anion gap is a calculation from sodium, chloride and bicarbonate that helps clinicians look into the acid-base balance of your blood.","url":"https://bloodtesttracker.com/markers/anion-gap","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}