Sudden neurological dysfunction caused by interruption of blood flow to part of the brain or bleeding within or around the brain.
A stroke occurs when part of the brain is deprived of adequate blood and oxygen because a blood vessel becomes blocked, or when a blood vessel ruptures and causes bleeding. The affected brain tissue can become damaged or die, potentially causing weakness, speech difficulties, vision problems, loss of coordination, or other neurological abnormalities.
Most strokes are ischemic, caused by blocked blood flow, while hemorrhagic strokes result from bleeding. Stroke is a medical emergency because rapid treatment can reduce brain injury and disability.
QUICK FACT
Stroke symptoms often begin suddenly. Common warning signs include facial weakness, arm weakness, and speech difficulty.
COMMONLY CONFUSED WITH
- Transient ischemic attack (TIA): temporary neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia without established infarction.
- Heart attack: involves damage to heart muscle from inadequate blood supply; stroke affects the brain or related nervous-system structures.
SEE ALSO
