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What is a stroke?

  • A stroke occurs when the flow of blood and oxygen to the brain is stopped or interrupted. This happens because of a burst (ruptured) or blocked blood vessel.

    A stroke can cause serious disability and can be life-threatening.

    The role of your brain and central nervous system

    Nerve cells in the brain (neurons) send signals to the rest of your body. These signals control your speech, movement, thinking process and senses (hearing, sight and touch).

    The part of your brain affected by a stroke determines how your body is affected.

    The right side of your brain controls the left side of your body. Usually, the right side of your brain controls the ability to pay attention, be aware of your own body, or recognize things you see, hear or touch.

    The left side of your brain controls the right side of your body. Usually, the left side of your brain controls the way you talk and understand speech.

    The base of your brain (brainstem) is connected to your spinal cord. The brainstem controls specialized functions, including:

    • your eye movements
    • swallowing
    • breathing
    • alertness

    Illustration of different parts of a nerve cell.
  • Source: Allina Health Patient EducationUnderstanding Stroke, fifth edition, neuro-ahc-90662
    Reviewed by: Allina Health Patient Education experts
    First published: 02/01/2006
    Last reviewed: 05/01/2018