In the United States, stroke affects more than 750,000 people each year. It's the leading cause of adult disability and is the fifth-leading cause of death.
On this page:
The Three Types of Stroke
The different types of stroke include:
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Stroke Causes
A stroke most often occurs when blood flow to the brain becomes blocked (called ischemic stroke).
One of the following problems may cause this blockage:
- A build-up of fatty substances (atherosclerotic plaque) along an artery's inner lining causes it to narrow, reduces its elasticity, and decreases its blood flow.
- A clot forms in an artery supplying blood to the brain.
- A clot forms somewhere in the body — often the heart — and breaks free, traveling to an artery supplying blood to the brain and becoming lodged there.
A stroke also may occur if a blood vessel breaks and bleeds into or around the brain. If this happens, it is called a hemorrhagic stroke.
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Stroke Symptoms
If you suspect someone is having a stroke, watch for these common warning signs:
- One-sided weakness
- Numbness on one side of face, arm, or leg
- Slurred or garbled speech
- Difficulty talking to or understanding others
- Loss of vision or difficulty seeing in one eye
- Double vision
- Difficulty with balance or coordination of arms or legs
- Severe headache (the worst headache of your life)
It’s important to call 911 immediately at any sign of a stroke.
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Diagnosing Stroke
Tests that help doctors diagnose stroke include:
- Neurological exams
- Blood tests
- Other tests to quickly determine the cause, location, and amount of damage
Imaging scans that can help diagnose stroke include:
- Computed tomography (CT) scan — a type of x-ray that uses a computer to make pictures of the brain.
- Magnetic resonance imaging (MRI) scan— a test that uses magnetic waves to make pictures of the brain.
- Arteriography (angiography) — shows arteries in the brain.
- Magnetic resonance angiography (MRA) — creates a of blood flow& in the brain's vessels.
- Functional MRI — shows brain activity by picking up signals from oxygenated blood.
- Doppler ultrasound — reveals narrowing of the arteries supplying blood to the brain.
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Stroke Resources
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