The Spectrum of Coagulation Abnormalities in Thyroid Disorders

The hemostatic balance is a complex system where the delicate equilibrium is regulated by several factors including hormones. A variety of endocrine disorders have been reported to be associated with coagulation abnormalities, ranging from mild laboratory changes to clinically relevant thrombotic or bleeding manifestations. In this review, we summarize the current knowledge on the main abnormalities of the coagulation and fibrinolytic systems associated with thyroid dysfunctions. Overall, although mostly based on uncontrolled studies, data in the literature suggest that patients with hyperthyroidism or subclinical hypothyroidism have a hypercoagulative state, whereas patients with overt hypothyroidism have a bleeding tendency.