. The PT is a test that measures the time it takes for blood to form a clot in the body. Normally, when a blood vessel is damaged, clotting factors will combine in a certain order to form a clot and quickly stop bleeding.
. It assesses the deficiencies of the coagulation factors of the extrinsic pathway, primarily factor VII, and the common pathway (II, V, and X), due to genetic deficiencies or acquired conditions such as liver disease.