Unfractionated heparin is a type of anticoagulant medication used to prevent and treat blood clots. It works by inhibiting certain proteins in the blood that promote clotting, thereby reducing the risk of conditions like deep vein thrombosis and pulmonary embolism. This medication is typically administered through an injection and requires careful monitoring of blood levels to ensure effectiveness and safety. Unlike other anticoagulants, unfractionated heparin has a variable response in different patients, which is why healthcare providers often adjust dosages based on individual needs. It is commonly used in hospitals, especially during surgeries or in patients with certain medical conditions that increase the risk of clot formation.