Thyroid Disorders and Hypocoagulability

This review focuses attention on some practical aspects of the relationship between thyroid disorders and hypocoagulability, as related to an impairment of hemostasis and fibrinolysis. An understanding of this topic in daily clinical practice is important given that the interaction between hemostatic abnormalities and thyroid disorders is still poorly recognized by the medical community. Even if the bleeding tendency is in general mild and may be reversed by restoration of an euthyroid state, severe hemorrhagic events may complicate the course of both hyper- and hypothyroidism, as precipitated by such conditions as thrombocytopenia, acquired von Willebrand syndrome, and acquired hemophilia. The pathogenesis of the hemostatic abnormalities resides in either the direct effect of thyroid hormones or some conditions in an autoimmune mechanism. Physicians and endocrinologists should pay close attention to both clinical hemorrhagic events in their patients as well as to any laboratory abnormalities identified by blood coagulation testing.