There are many causes to vessel defects eg. hereditary (ie Ehlers Danlos syndrome), nutrient deficiency (i.e. Vitamin C deficiency), drug induced (ie steroid induced), aging (senile purpura), certain infections (ie streptococcal, meningococcal infections), malignancies (i.e. lymphoma, leukemia), etc.
The platelet disorders are often subdivided into either quantitative (ie thrombocytopenia) or qualitative problems ( i.e. platelet dysfunction). The former can be a result of decreased platelet production in the bone marrow or an increased destruction/loss of platelets in the peripheral blood stream. The causes can likewise be a primary platelet disorder (e.g. hereditary, nutrient deficiency, infections, drug induced, etc.) or secondary to other disease states affecting the marrow or peripheral blood (e.g. other malignancies, autoimmune disorder, etc).
Clotting defects can either be due to an abnormal production or an accelerated removal of the fiber clots. The common cause of defective production is the hereditary deficiency of clotting factors (e.g. hemophilia, von Willebrand disease, etc). The problem with an accelerated removal of fiber clots is by far very rare, but nevertheless, could still result from a deficiency of the regulatory proteins in clot removal (e.g. plasminogen activator inhibitor deficiency).
