Bleeding may occur as a result of disorders of platelets, clotting factors or blood vessels. Vascular-related bleeding caused by disturbances in the blood vessels themselves. Typically, petechiae, purpura and bruising occur here (except in hereditary haemorrhagic telangiectasia), but rarely leads to severe blood loss. The bleeding may be the result of a lack of vascular or perivascular collagen as in Ehlers-Danlos syndrome or other rare hereditary tissue diseases (e.g. B. pseudoxanthoma elasticum, osteogenesis imperfecta, Marfan syndrome;. Marfan syndrome). Bleeding (vitamin C deficiency), the Henoch-Schonlein Purpura, or a hypersensitive-induced vasculitis be (with vitamin C deficiency) also one of the main manifestations of scurvy, which often occurs in childhood (immunoglobulin-A-associated vasculitis (IGAV )). In vascular related bleeding disorders clotting tests are usually normal. the diagnosis is made clinically for most disorders; specific tests are available for some disorders.