Normally, when an injury that causes bleeding occurs, the body sends out signals that cause blood to clot at the wound, and then the clot naturally breaks down as the wound heals. A person prone to abnormal clotting has an imbalance between clot formation and clot breakdown.
Warfarin prevents new clots from forming and prevents existing clots from growing by stopping the production of certain proteins that are needed for blood to clot. Warfarin does not break up or dissolve existing blood clots. Warfarin is a type of anticoagulant medicine.
Warfarin is used to prevent or treat deep vein thrombosis and pulmonary embolism.1 If you have a high risk of these problems, such as having a recent surgery, you might take warfarin for a short time, about a few weeks. If you have had deep vein thrombosis or pulmonary embolism, you might take warfarin for a longer time, such as 3 months or longer. The length of time will vary based on your health.
Warfarin reduces the chance that a new blood clot will form or that an existing blood clot will get larger.