Although Xarelto and other anticoagulants are used to prevent blood clotting, there are some instances in which clotting actually becomes a life-saving body function. When the body bleeds, its natural defense mechanism is to clot the blood to slow the bleeding. But if a person is unable to form these blood clots because they are on a blood thinner, this can increase the risk of permanent Xarelto bleeding injuries or, in extreme cases, even death.