How Strokes Happen

There are two basic types of strokes, or cerebral vascular accidents (CVAs): ischemic and hemorrhagic.

Ischemic Stroke

Ischemic stroke occurs when blood vessels to the brain become narrowed or clogged, preventing or slowing blood flow to the brain. There are three types of ischemic strokes: thrombotic, embolic and systemic hypoperfusion.

  • THROMBOTIC - Caused by a blood clot (thrombus) in an artery going to the brain. Blood clots usually form in arteries damaged by arteriosclerosis (hardening of the arteries).
  • EMBOLIC - Caused by a wandering clot (embolus) formed usually in the heart or neck arteries.
  • SYSTEMIC HYPOPERFUSION - Decreased blood flow because of decreased circulation caused by the heart itself. The heart’s pumping action fails and too little blood reaches the brain.

Hemorrhagic Stroke

Hemorrhagic stroke occurs when a blood vessel ruptures in or near the brain. There are two kinds of hemorrhagic strokes: subarachnoid and intracerebral.

  • SUBARACHNOID - Occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull. A ruptured aneurysm, often caused by high blood pressure, is the most common cause. An aneurysm is a blood-filled pouch that balloons out from an artery wall.
  • INTRACEREBRAL - Occurs when a blood vessel bleeds into the tissue deep within the brain. Chronically high blood pressure or aging vessels are the main causes of this type of stroke.

The warning signs are many and may include just a few of the following: severe headaches, dizziness, nausea, projectile vomiting, decrease in balance, decrease in vision, increase in confusion, trouble speaking or understanding, sudden weakness of face, arm, leg especially on one side of the body, and tingling or numbness that doesn’t get better in an hour or so.