A blood sample is drawn from a vein, and the lab measures how long it takes for the blood to clot after adding tissue factor and calcium.

PT ranges vary by lab and reagents, but many adults not on anticoagulants have a PT roughly around 10–13 seconds.

It may indicate that the blood clots more slowly than normal, which can be due to warfarin effect, liver disease, vitamin K deficiency, anticoagulant therapy, or certain medications.

Unless advised by the healthcare professional, there’s no specific fasting required for PT. Inform your clinician about vitamins, supplements, or medicines that affect clotting (e.g., vitamin K-rich foods, anticoagulants).

PT test at home or your nearest location can be possible by collection of samples with a home collection facility. The home collection facility enables you to get PT tests near your preferred area or location and is convenient and easy.