Pro time is the shortened name of the prothrombin time test, which measures how long it takes the plasma to clot, explains MedlinePlus. The prothrombin time test is used to diagnose bleeding and clotting disorders, monitor people taking blood-thinning medications and look for the underlying causes of abnormal bleeding.
A normal prothrombin time ranges from 11 to 13.5 seconds in people who do not take blood thinners, states MedlinePlus. Increased clotting times are caused by bleeding disorders, liver disease, vitamin K deficiency and disseminated intravascular coagulation. DIC causes small clots to form inside the blood vessels, reducing the number of platelets in circulation, explains NYU Langone Medical Center. The lack of platelets causes bleeding to occur in other parts of the body.
People who take blood thinners generally have a target prothrombin time of 1 1/2 times the normal value, states the Cleveland Clinic. Target prothrombin times vary depending on why a person is taking medication to prevent blood clots, reports MedlinePlus. Drinking alcohol or taking the wrong dose of medication can cause prothrombin time to be too high or too low. A person who is taking blood thinners should not take any vitamins, supplements or over-the-counter medications without checking with a doctor. It is also necessary to avoid or limit the consumption of foods that affect the way blood thinners work.