What is a stroke?

A stroke is caused by a disruption to the brain's blood supply

Ischaemic stroke

Haemorrhagic stroke

There are two main types:


  • An ischaemic stroke is caused by blockage of a blood vessel that supplies the brain. It accounts for around 85% of strokes.

  • A haemorrhagic stroke happens when a vessel in the brain bursts.

A transient ischaemic attack, or ‘mini-stroke’, is caused by a temporary clot. Symptoms resolve within 24 hours. However, it should be taken seriously as there’s significantly higher risk of getting having a full stroke in the near future. 

Stroke risk

The risk of stroke increases with age because arteries get narrower and more stiff as we get older. Although there’s not much we can do about this one, there's plenty we can do about other risk factors. 



Smoking causes build up of plaques in arteries which reduce blood flow and make a clot more likely.  


High blood pressure, cholesterol & blood sugar (diabetes)  

When these elements are not properly controlled there’s damage to blood vessels, either by weakening the wall or narrowing the tube. 

Atrial fibrillation

This is an irregular heart beat. The heart may not pump blood as efficiently as it should and blood clots are more likely to form. If a blood clot forms in your heart it can be pumped through the bloodstream and block a small artery in the brain, causing a stroke.