Ischemic Stroke (Clots)

What is an Ischemic Stroke?

Ischemic stroke occurs when a vessel supplying blood to the brain is obstructed. It accounts for about 87 percent of all strokes.

Fatty deposits lining the vessel walls, called atherosclerosis, are the main cause for ischemic stroke. Fatty deposits can cause two types of obstruction:

  • Cerebral thrombosis is a thrombus (blood clot) that develops at the fatty plaque within the blood vessel.
  • Cerebral embolism is a blood clot that forms at another location in the circulatory system, usually the heart and large arteries of the upper chest and neck. Part of the blood clot breaks loose, enters the bloodstream and travels through the brain’s blood vessels until it reaches vessels too small to let it pass. A main cause of embolism is an irregular heartbeat called atrial fibrillation. It can cause clots to form in the heart, dislodge and travel to the brain.

Silent Stroke

Silent cerebral infarction (SCI), or “silent stroke,” is a brain injury likely caused by a blood clot that interrupts blood flow in the brain. It’s a risk factor for future strokes and a sign of progressive brain damage.

Use the letters in "F.A.S.T." to spot signs of a stroke and know when to call 9-1-1.

By learning and sharing the F.A.S.T. warning signs, you just might save a life from stroke.

Spot a stroke F.A.S.T.
woman with wheelchair at home

Support Network

Want to share recovery and rehabilitation experiences with other survivors? Find reassurance or offer your own words of wisdom on the American Heart / American Stroke Association's Support Network.