Science
What is a stroke?
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.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains a stroke.
Key things to understand
- 1Brain cells need a constant supply of oxygen-rich blood.
- 2A stroke blocks or bursts a blood vessel in the brain.
- 3Starved cells start dying within minutes.
- 4Effects depend on which brain area is hit — speech, movement, vision.
- 5Acting fast ('time is brain') greatly improves recovery.
Frequently asked questions
- 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.