Causes of a Stroke

What are the causes of stroke?

An ischemic stroke is when there is an obstruction of blood flow to the brain. This is usually as a result of a blood clot which causes a partial or complete obstruction of the artery. If the clot develops in the affected artery then it is known as a thrombus (thrombotic stroke) or it can dislodge from elsewhere in the circulatory system and block the artery in the brain which is known as an embolus (embolic stroke).
In a hemorrhagic stroke, there is a rupture of blood vessels that carry blood to the brain. It usually occurs at a site where there is a weakening of the blood vessel wall known as an aneurysm. An adequate supply of blood can therefore not reach the brain tissues.
In both these cases, there is injury of the brain tissue as it is starved of oxygen.