About 4,000 people suffer strokes in Northern Ireland each year. More and more young people are being affected.
Stroke causes brain tissue to die
Many people risk death or disability because they do not know enough about stroke, or its risk factors.
The BBC news website spoke to Myrtle Neill, Director of Health, NI Chest, Heart and Stroke about the condition's 10 common myths.
Am I too young to have a stroke?
One in four strokes occurs in people under 65. That's more than 1,000 people a year in Northern Ireland. Stroke has been known in teenagers and in children.
I smoke only moderately, so am I not at risk?
Any amount of inhaled tobacco smoke contributes towards artery damage.
You may not smoke a lot, but combine it with other lifestyle factors and your risk may increase substantially.
As a vegetarian, am I safe?
Animal products are not the only source of saturated fat, which contributes towards stroke risk.
In addition, some processed vegetarian foods contain high levels of salt, which increases blood pressure - one of the main risk factors.
I protect myself by walking once a week. Is that enough?
It's better than nothing, but not nearly good enough.
You need to take brisk physical exercise for 30 minutes at least three times a week.
I only drink alcohol once a week, so does that reduce my risk?
It depends how much you drink.
Binge drinking actually increases your risk. Stick to the recommended alcohol limits.
Most people recover from stroke, don't they?
This year, over 4,000 people in Northern Ireland will suffer a stroke.
One third will die, one third will be left with a permanent disability and only the remaining third will recover completely.
Is a stroke a brain haemorrhage?
In fact, only one in five strokes is caused by bleeding in the brain.
The other 80% are caused by blockages, usually clots, in the blood vessels.
Are women less at risk than men?
Over the course of a lifetime, a woman is more likely to have a stroke, although men tend to have them at a younger age.
Women are also statistically more likely to die from the condition. Stroke claims more female lives than breast cancer.
Stroke cannot be prevented. Is that right?
On the contrary, many strokes are preventable. Some risk factors, such as family history, cannot be changed.
But others, such as smoking, high blood pressure, excess body weight and exercise habits, can. Prompt treatment of a mini stroke may prevent a full blown stroke.
Is physical disability the only effect of stroke?
No. People can undergo personality changes and suffer from depression.
In addition, speech and communication can be affected. Reading and writing, which we often take for granted, may also have to be relearned.