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What is a stroke?

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Quick answer

A stroke happens when blood flow to part of the brain is suddenly cut off, starving brain cells of oxygen so they begin to die. It's a medical emergency — fast treatment can save brain tissue and prevent lasting damage.

Key things to understand

  1. Brain cells need a constant supply of oxygen-rich blood.
  2. A stroke blocks or bursts a blood vessel in the brain.
  3. Starved cells start dying within minutes.
  4. Effects depend on which brain area is hit — speech, movement, vision.
  5. Acting fast ('time is brain') greatly improves recovery.

People also ask

What are the two main types of stroke?
Ischemic (a clot blocks a vessel) and hemorrhagic (a vessel bursts and bleeds); both cut off oxygen to brain cells.
Why is fast treatment so important in a stroke?
Brain cells die quickly without oxygen, so every minute counts — rapid treatment can save tissue and reduce lasting disability.
What are warning signs of a stroke?
Sudden face drooping, arm weakness, and slurred speech — remembered as 'FAST,' a signal to call emergency services immediately.