STROKE
What is Stroke?
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An ischemic stroke occurs when the blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes.
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A stroke is a medical emergency, and prompt treatment is crucial. Early action can reduce brain damage and other complications.
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The good news is that many fewer Americans die of stroke now than in the past. Effective treatments can also help prevent disability from stroke.
Symptoms​
If you or someone you're with may be having a stroke, pay particular attention to the time the symptoms began. Some treatment options are most effective when given soon after a stroke begins.
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Signs and symptoms of stroke include:
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Trouble speaking and understanding what others are saying. You may experience confusion, slur words or have difficulty understanding speech.
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Paralysis or numbness of the face, arm or leg. You may develop sudden numbness, weakness or paralysis in the face, arm or leg. This often affects just one side of the body. Try to raise both your arms over your head at the same time. If one arm begins to fall, you may be having a stroke. Also, one side of your mouth may droop when you try to smile.
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Problems seeing in one or both eyes. You may suddenly have blurred or blackened vision in one or both eyes, or you may see double.
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Headache. A sudden, severe headache, which may be accompanied by vomiting, dizziness or altered consciousness, may indicate that you're having a stroke.
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Trouble walking. You may stumble or lose your balance. You may also have sudden dizziness or a loss of coordination.
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Causes
There are two main causes of stroke: a blocked artery (ischemic stroke) or leaking or bursting of a blood vessel (hemorrhagic stroke). Some people may have only a temporary disruption of blood flow to the brain, known as a transient ischemic attack (TIA), that doesn't cause lasting symptoms.
Ischemic stroke
This is the most common type of stroke. It happens when the brain's blood vessels become narrowed or blocked, causing severely reduced blood flow (ischemia). Blocked or narrowed blood vessels are caused by fatty deposits that build up in blood vessels or by blood clots or other debris that travel through the bloodstream, most often from the heart, and lodge in the blood vessels in the brain.
Transient ischemic attack (TIA)
A transient ischemic attack (TIA) sometimes known as a ministroke is a temporary period of symptoms similar to those in a stroke. A TIA doesn't cause permanent damage. A TIA is caused by a temporary decrease in blood supply to part of the brain, which may last as little as five minutes.
Like an ischemic stroke, a TIA occurs when a clot or debris reduces or blocks blood flow to part of the nervous system.
Seek emergency care even if you think you've had a TIA because your symptoms got better. It's not possible to tell if you're having a stroke or TIA based only on the symptoms. If you've had a TIA, it means you may have a partially blocked or narrowed artery leading to the brain. Having a TIA increases your risk of having a full-blown stroke later.
Hemorrhagic stroke
Hemorrhagic stroke occurs when a blood vessel in the brain leaks or ruptures. Brain hemorrhages can result from many conditions that affect the blood vessels. Factors related to hemorrhagic stroke include:
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Uncontrolled high blood pressure
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Overtreatment with blood thinners (anticoagulants)
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Bulges at weak spots in your blood vessel walls (aneurysms)
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Trauma (such as a car accident)
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Protein deposits in blood vessel walls that lead to weakness in the vessel wall (cerebral amyloid angiopathy)
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Ischemic stroke leading to hemorrhage
A less common cause of bleeding in the brain is the rupture of an irregular tangle of thin-walled blood vessels (arteriovenous malformation).
