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Stroke Health Center

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How Atherosclerosis Causes Half of All Strokes

Having a stroke is one of the most frightening prospects of aging. Strokes can come on suddenly, stealing the use of an arm or the ability to speak. A stroke can be fatal or leave us permanently disabled.

About half of all strokes are caused by atherosclerosis -- the same process of narrowing and hardening of the arteries that causes heart attacks. Atherosclerosis progresses silently, without symptoms, putting our brains and our independence at risk.

Recommended Related to Stroke

Understanding Stroke -- Symptoms

You should consider these symptoms warning signs and consult your health care provider: Sudden weakness or numbness in the face, arm, or leg on one side of the body. Abrupt loss of vision, strength, coordination, sensation, speech, or the ability to understand speech. These symptoms may become worse over time. Sudden dimness of vision, especially in one eye. Sudden loss of balance, possibly accompanied by vomiting, nausea, fever, hiccups, or trouble with swallowing. Sudden and severe...

Read the Understanding Stroke -- Symptoms article > >

Reducing the risk factors for atherosclerosis lowers the risk of stroke. Making a few lifestyle changes can protect your brain from this common cause of strokes.

Facts About Atherosclerosis and Stroke

  • About 700,000 strokes occur each year in the U.S.
  • One in five people will have a stroke in his or her lifetime.
  • One-quarter of strokes are fatal.
  • Stroke is the third-leading cause of death in the U.S., behind heart disease and cancer.

Although most strokes are survivable, most people never recover completely after a stroke. Around a quarter of those who survive are permanently disabled.

There are two main types of strokes:

Ischemic: An artery inside or leading to the brain becomes completely blocked. Usually this is caused by a blood clot that forms in a clogged artery. It can also be due to a blood clot traveling to the brain from the heart.

Most strokes (about 87%) are ischemic, and most of those are caused by atherosclerosis.

Hemorrhagic: These strokes are caused by bleeding into the brain. Most commonly, high blood pressure causes a small artery to burst open. Abnormal blood vessels (such as aneurysms and arteriovenous malformations) are particularly likely to rupture. The bleeding disrupts healthy blood flow to brain tissue.

Hemorrhagic strokes are less common, making up about 13% of all strokes.

Regardless of whether a stroke is caused by atherosclerosis or bleeding, the symptoms are the same:

  • Sudden weakness on one side (in the face, arm, or leg)
  • Slurred speech or inability to remember words
  • Sudden blurry or double vision

Within hours of a stroke's onset, brain tissue dies from lack of oxygen and nutrients, leaving permanent damage.

If stroke-like symptoms strike, the time to call for help is now. Only prompt medical attention can help prevent permanent damage from a stroke.

With these sobering facts in mind, it's worthwhile to understand the process by which atherosclerosis causes strokes.

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