Anticoagulants are medicinal substances that prevent or stop the clotting of blood. Heparin, a naturally occurring anticoagulant extracted from animal tissues, works to stop the coagulation of blood by preventing the formation of prothrombin, fibrin and thrombin.

Anticoagulants are often used to treat bedridden patients who are at risk of developing blood clots in the veins of the legs and pelvis. Physical therapy reduces the risk of clots circulating to the lungs, heart, or other organs.

Anticoagulant medications are also often used to help prevent thrombosis, heart attack and stroke.