Anticoagulants are medications that are used to prevent blood clotting in the body. They work by inhibiting certain clotting factors in the blood, thereby reducing the risk of blood clots forming in blood vessels. Anticoagulants are commonly used to treat and prevent conditions such as deep vein thrombosis, pulmonary embolism, atrial fibrillation, and stroke. They are also used in patients undergoing certain medical procedures, such as surgery or dialysis. Anticoagulants can be taken orally or administered via injection, and they must be carefully monitored to ensure that the correct dosage is being used to prevent both clotting and excessive bleeding.