Disturbances of microcirculation play a significant role in the development and progression of acute and chronic cerebrovascular diseases (CVD). One of the reasons of prothrombogenic state of the endothelium is the increase of the number of blood corpuscles' leading to myeloproliferative disorders (non-Ph) (MPD). Headache was one of the most prominent clinical symptoms of CVD. It is often preceded the hematological diagnosis. Often headache is associated with focal vascular lesions on the magnetic resonance imaging. Acute cerebral events occurring as a result of thrombotic occlusion of the one or several carotid arteries tend to exhibit a fluctuating clinical course the latter being closely linked to the dynamics of thrombus progression. Our data suggest that the decrease in vascular wall elasticity and its athrombogenic properties may lead to a pathologic change in endothelial function consequently leading to stroke. An important clinical feature of the mentioned CVD is the young age of patients this underlines the necessity of hematological tests in cases with cryptogenic stroke.