{"id":"pt","name":"Prothrombin Time (PT)","shortName":"PT","aliases":["PT (Thromborel-S)","Prothrombin Time","PT","Protime","PT (Seconds)","Pro Time","PT, Patient","Prothrombin Time, Plasma","PT, Plasma","Prothrombin Time, P","Prothrombin Time (PT), P","Quick's Time","Tiempo de protrombina","Prothrombinzeit"],"abbreviations":["PT","Pro Time"],"loinc":[{"code":"5902-2","primary":true},{"code":"42638-7","primary":false},{"code":"34528-0","primary":false}],"specimen":"plasma","units":[{"ucum":"s","display":"seconds"}],"referenceRanges":[{"population":"Adults","low":9.4,"high":12.5,"unit":"s","unitDisplay":"seconds","note":"Mayo Clinic Laboratories interval for adults (coagulometric, turbidimetric method). PT ranges depend on the reagent and analyzer, so labs differ a lot: ARUP publishes 12.0–15.5 seconds (3.2% sodium citrate), and Indiana University Health lists 9.3–13.5 seconds. A UK haemostasis reference says a typical normal sample falls between 13 and 15 seconds and that each lab should set its own range. Use the range printed on your own report. Newborns and infants have their own ranges.","sources":[{"title":"Prothrombin Time, Plasma (test ID PTTP)","url":"https://www.testcatalog.org/show/PTTP","publisher":"Mayo Clinic Laboratories (Extended Catalog, via testcatalog.org)"},{"title":"Prothrombin Time (test 0030215)","url":"https://ltd.aruplab.com/Tests/Pub/0030215","publisher":"ARUP Laboratories"},{"title":"Thrombosis & Hemostasis Reference Ranges (updated 1/11/2021)","url":"https://cdn.iuhealth.org/resources/Thrombosis-Hemostasis-Ref-Ranges-No-StarMax.pdf","publisher":"Indiana University Health Pathology Laboratory","year":2021},{"title":"Prothrombin Time [PT]","url":"https://www.practical-haemostasis.com/Screening%20Tests/pt.html","publisher":"Practical-Haemostasis.com"},{"title":"Pre-Analytical Variables","url":"https://www.practical-haemostasis.com/Quality%20Assurance/pre_analytical_variables.html","publisher":"Practical-Haemostasis.com"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"How many seconds your blood plasma takes to clot in the lab. It checks several clotting proteins and is used to follow warfarin.","url":"https://bloodtesttracker.com/markers/pt","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}