{"id":"methemoglobin","name":"Methemoglobin (MetHb)","shortName":"MetHb","aliases":["Methemoglobin","MetHb","Methemoglobin, Blood","Met-Hb","Methemoglobin %","MetHgb","FMetHb","Methemoglobin, Quantitative","Methaemoglobin","Methemoglobin Quant","Ferrihemoglobin"],"abbreviations":["MetHb","Met-Hb","MetHgb","FMetHb"],"loinc":[{"code":"2614-6","primary":true},{"code":"2617-9","primary":false},{"code":"2615-3","primary":false},{"code":"15082-1","primary":false}],"specimen":"whole-blood","units":[{"ucum":"%","display":"%"},{"ucum":"1","display":"fraction (0–1)"}],"referenceRanges":[{"population":"Adults","low":0,"high":1.5,"unit":"%","unitDisplay":"%","note":"Mayo Clinic Laboratories (test MET, as listed by Michigan Medicine Laboratories) and Geisinger Medical Laboratories both print 0.0–1.5% of total hemoglobin for ages 1 year and older. The University of Washington prints less than 3.0%. European hematology recommendations say healthy blood contains less than 1% methemoglobin, and a study of 134 healthy adults measured 0.3–0.9% on venous blood. Labs set their own limits and instruments differ a little, so use the range printed on your report. Adult values only.","sources":[{"title":"Methemoglobin and Sulfhemoglobin, Blood (Mayo Clinic Laboratories test MET)","url":"https://mlabs.umich.edu/tests/methemoglobin-and-sulfhemoglobin-blood","publisher":"Michigan Medicine Laboratories (MLabs), send-out to Mayo Clinic Laboratories"},{"title":"Methemoglobin, Whole Blood","url":"https://www.geisingermedicallabs.com/catalog/Details?tid=1292","publisher":"Geisinger Medical Laboratories"},{"title":"Recommendations for diagnosis and treatment of methemoglobinemia (Joint EHA and EuroBloodNet recommendations)","url":"https://doi.org/10.1002/ajh.26340","publisher":"American Journal of Hematology 2021;96:1666-1678","year":2021},{"title":"Reference intervals for venous blood gas measurement in adults","url":"https://doi.org/10.1515/cclm-2020-1224","publisher":"Clinical Chemistry and Laboratory Medicine 2021;59(5):947-954","year":2021}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The share of your hemoglobin in a form that can't carry oxygen well. Labs usually report up to about 1.5%, and higher levels can cause blue-gray skin.","url":"https://bloodtesttracker.com/markers/methemoglobin","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}