How atherosclerosis causes half of all strokes

Having a stroke is one of the most frightening prospects of ageing. Strokes can come on suddenly, taking away 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 us at risk of a stroke.

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.

Atherosclerosis as a cause of stroke: facts and stats

• About 130,000 strokes occur each year in the UK.
• One in ten people will have a stroke in their lifetime.
• One-quarter of strokes are fatal.
• Stroke is the third-leading cause of death in the UK, 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:

Ischaemic: An artery inside or leading to the brain becomes completely blocked. Usually this is caused by a blood clot that forms on an area of atherosclerosis. It can also be due to a blood clot travelling to the brain from the heart.

Most strokes (about 80%) are ischemic, and most of those are caused by atherosclerosis.

Haemorrhagic: 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.

Haemorrhagic strokes are less common, making up about 20% 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
• Problems speaking: 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 999 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.