'Stroke is a rapidly developed clinical sign of focal disturbances of cerebral function lasting more than 24 hours or leading to death'. (WHO)
Inspite of the presence of factors inhibiting the coagulation of blood within vessels, clotting may occur at times. Such clots frequently are formed in veins than in arteries. The blood clot or thrombus formed in the streaming blood is called thrombosis. A clot in the cerebral vessel is called stroke or cerebral thrombosis. Stroke may be caused due to vascular occlusion, which is a blockage in the cerebral artery. The occlusion and stroke lead to infarction. The infarction leads to abnormal symptoms in the brain.
Vascular occlusion is of two types viz., Thrombotic and embolic. An embolus is a portion of the thrombus clot that becomes detached and enters into circulating blood. An embolus may block the circulation to vital parts leading to serious consequences.
Stroke causes both physical; and mental crippling. It is a worldwide health problem. It can occur at any age. Several risk factors may lead to stroke and brain haemorrhage. They are cardiac abnormalities, diabetes, elevated blood lipids, hypertension, obesity, smoking and stenosis (narrowing of valvular orifice), etc.
One can control stroke by controlling the above risk factors.