In medicine (hematology), bleeding diathesis is an unusual susceptibility to bleed (hemorrhage) mostly due to hypocoagulability (a condition of irregular and slow blood clotting), in turn caused by a coagulopathy (a defect in the system of coagulation).

[citation needed] Acquired causes of coagulopathy include anticoagulation with warfarin, liver failure, vitamin K deficiency and disseminated intravascular coagulation.

[citation needed] Bleeding diathesis may also be caused by impaired wound healing (as in scurvy), or by thinning of the skin, such as in Cushing's syndrome.

[citation needed] Some people lack genes that typically produce the protein coagulation factors that allow normal clotting.

Various types of hemophilia and von Willebrand disease are the major genetic disorders associated with coagulopathy.

Gene therapy is a source of active research that hold promise for the future.