{"id":"fibrinogen","name":"Fibrinogen Activity","shortName":"Fibrinogen","aliases":["Fibrinogen","Fibrinogen, Functional","Fibrinogen Clauss","Fibrinogen Level","Factor I","Fibrinogen (Factor I)","Fibrinogen Activity, Clauss","Fibrinogen, Plasma","Clauss fibrinogen","Fibrinogen Activity","Functional Fibrinogen","Fibrinogen, Quantitative","Fibrinogen Functional (Clauss)","Fibrinogen, Clauss, Plasma","PT-Derived Fibrinogen","Fibrinogen, Derived"],"abbreviations":[],"loinc":[{"code":"3255-7","primary":true},{"code":"42568-6","primary":false},{"code":"48664-7","primary":false}],"specimen":"plasma","units":[{"ucum":"mg/dL","display":"mg/dL"},{"ucum":"g/L","display":"g/L"}],"referenceRanges":[{"population":"Adults","low":200,"high":393,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Adult interval from Mayo Clinic Laboratories for its main fibrinogen test (200–393 mg/dL). Mayo lists 200–500 mg/dL for its Clauss test (the same for men and women), ARUP lists 150–430 mg/dL, Cleveland Clinic Laboratories lists 200–400 mg/dL, and Croatian national recommendations quote about 1.8–4.0 g/L (180–400 mg/dL) as a general adult interval, so labs differ and the range on your report is the one to use. Fibrinogen rises through pregnancy (a pilot study of 71 women found significant increases in each trimester), so a lab's usual range can flag results that are typical in pregnancy. No wellness target is given: in large studies the link between fibrinogen and heart attack or stroke rises steadily with no clear threshold (Fibrinogen Studies Collaboration).","sources":[{"title":"Fibrinogen, Plasma (test FIBTP)","url":"https://www.testcatalog.org/show/FIBTP","publisher":"Mayo Clinic Laboratories (Extended Catalog)"},{"title":"Fibrinogen, Clauss, Plasma (test CLFIB)","url":"https://www.testcatalog.org/show/CLFIB","publisher":"Mayo Clinic Laboratories (Extended Catalog)"},{"title":"Fibrinogen (ARUP test 0030130)","url":"https://ltd.aruplab.com/Tests/Pub/0030130","publisher":"ARUP Laboratories"},{"title":"Fibrinogen (test directory entry)","url":"https://clevelandcliniclabs.com/test/fibrinogen/","publisher":"Cleveland Clinic Laboratories"},{"title":"Croatian Society of Medical Biochemistry and Laboratory Medicine: National recommendations for blood collection, processing, performance and reporting of results for coagulation screening assays prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen and D-dimer","url":"https://pubmed.ncbi.nlm.nih.gov/31223257/","publisher":"Biochemia Medica","year":2019},{"title":"Reference Values of D-Dimers and Fibrinogen in the Course of Physiological Pregnancy: the Potential Impact of Selected Risk Factors-A Pilot Study","url":"https://pubmed.ncbi.nlm.nih.gov/32596295/","publisher":"BioMed Research International","year":2020},{"title":"Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis","url":"https://pubmed.ncbi.nlm.nih.gov/16219884/","publisher":"JAMA (Fibrinogen Studies Collaboration)","year":2005}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"Measures how much working fibrinogen, the protein that forms the mesh of a blood clot, is in your blood.","url":"https://bloodtesttracker.com/markers/fibrinogen","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}