Most younger people who suffer a stroke have been healthy, unaware of an underlying problem.
Strokes occur when a blood vessel ruptures and blood leaks into the brain.
They become more common as people age.
The most common cause is high blood pressure, but strokes can also be caused by a heart abnormality.
A person can live for decades without knowing they have a weak artery before it ruptures.
Smoking, poor diet and excessive drinking also increase the risk.
The damage depends on which area of the brain is affected.
Speech, which is lost when the left side of the brain is injured, is a good indicator of recovery.