| Risk Factors Stroke is a brain injury. It occurs when the
blood supply to the brain is interrupted. Without oxygen and
nutrients from blood, brain tissue dies in less than 10 minutes.
The tissue death causes a sudden loss in function. A stroke
occurs when there is a loss of blood flow. It may happen because
of a blockage in blood flow, called ischemic stroke, or because
of bleeding in the brain, called hemorrhagic stroke. A sudden
decrease in the flow of blood may be caused by: A clot that
breaks off from another part of the body (such as the heart or
neck) and lodges in blood vessel of neck or brain—there are
certain conditions which predispose people to form blood clots,
such as: - A blood clot that forms in neck or brain —a build-up
of fatty substances along the inner lining of the artery that
gradually decrease the area the blood can flow through -
Inflammatory conditions in the blood vessels (vasculitis)
Hemorrhagic stroke occur when blood vessels break and bleed into
or around the brain. This can happ