What is a stroke?

A stroke occurs when a blood vessel (artery) that supplies blood to the brain bursts or is blocked by a blood clot. Within minutes, the nerve cells in that area of the brain are damaged, and they may die within a few hours. As a result, the part of the body controlled by the damaged section of the brain cannot function properly.

If you have symptoms of a stroke, you need emergency care, just as though you are having a heart attack. If medical treatment begins soon after symptoms are noticed, fewer brain cells may be permanently damaged.

What causes a stroke?

  • An ischemic stroke is caused by a reduction in blood flow to the brain. This can be caused by a blockage or narrowing in an artery that supplies blood to the brain or when the blood flow is reduced because of a heart or other condition.
  • A hemorrhagic stroke develops when an artery in the brain leaks or bursts and causes bleeding inside the brain tissue or near the surface of the brain.

Before having a stroke, you may have one or more transient ischemic attacks (TIAs), which are warning signals that a stroke may soon occur. TIAs are often called mini-strokes because their symptoms are similar to those of a stroke. However, unlike stroke symptoms, TIA symptoms usually disappear within 10 to 20 minutes, although they may last up to 24 hours.

What are the symptoms?

Symptoms of a stroke begin suddenly and may include:

  • Numbness, weakness, or paralysis of the face, arm, or leg, especially on one side of the body.
  • Vision problems in one or both eyes, such as double vision or loss of vision.
  • Confusion, trouble speaking or understanding.
  • Trouble walking, dizziness, loss of balance or coordination.
  • Severe headache.

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