Our Prothrombin Time (INR) Blood Test gives you your international normalized ratio (INR), which is calculated based on the results of your prothrombin time (PT) test. INR is a laboratory measurement of how long it takes for blood to form a clot.

You can use our PT test if you are being treated with blood-thinning medication (anticoagulant) warfarin (Coumadin®) to monitor your treatment.

Your clotting cells (platelets) are produced in the bone marrow and help control bleeding. Sometimes too few platelets are produced or are destroyed too quickly, resulting in a condition known as thrombocytopenia. This can be caused by immune disorders, some medication, liver disease, or chronic bleeding. A high platelet count is called thrombocytosis and can be caused by several conditions, including bone marrow disorders, infection and inflammation. Read more about what blood is, the different blood types, and the main functions of blood in our blog: what is blood and what does it do?