PT and PTT

PT and PTT

$ 53.99

The prothrombin time (PT) w/INR test measures the length of time it takes for a blood clot to form in a sample of blood. Partial Thromboplastin Time (PTT) test is ordered when someone has unexplained bleeding or clotting. The PTT test is usually used as a starting place when investigating the cause of a bleeding or thrombotic episode.

A blood clot forms following the successful and timely completion of a sequence of events known as the coagulation cascade, in which coagulation factors are activated one after the other. In order for the process to work effectively, an adequate quantity of each coagulation factor must be present, and each must function properly. An insufficient quantity can result in prolonged bleeding, while excess quantity can result in too much clotting. The PT test evaluates factors I, II, V, VII and X, while the PTT test evaluates factors I, II, V, VIII, IX, X, XI and XII, as well as prekallikrein (PK) and high molecular weight kininogen (HK). The combination of both tests examines how the factors work together, and evaluation of both results together can help diagnose certain conditions.

The PT and PTT Blood Tests are useful in the diagnosis of excessive, unexplained bleeding in patients who are not taking blood-thinning medications. These bleeding disorders include conditions such as nosebleeds, bruising, heavy menstrual periods, blood in the stool and/or urine, and bleeding gums, among others. The tests are also sometimes ordered for patients prior to surgery to ensure normal clotting ability.


After placing an order, you will receive a doctor approved lab order by email usually within 20-30 minutes. The emailed Lab Requisition will allow you to go to a local patient collection site to get tested. You will not have to pay any additional lab, collection or doctor's fees.  Most test will normally report within 48-72 hours by secure email. List of collections site can be found using our Lab Locator Tool. If you have any questions please call our offices at 1-844-455-6355 or chat online with a member of our Care Team.