- An ischaemic stroke is the most common form of stroke (accounting for around 85% of all strokes), caused by a clot blocking or narrowing an artery carrying blood to the brain. The likelihood of suffering an ischaemic stroke increases with age.
- A haemorrhagic stroke is a less common form of stroke caused when a weakened blood vessel supplying the brain bursts and causes brain damage. It accounts for around 15% of all strokes but its mortality risk is greater than for ischaemic stroke.
A Transient Ischaemic Attack (TIA) is a temporary stroke that occurs when the blood supply to part of the brain is cut off for a short time only. The symptoms are very similar to an ischaemic stroke but are temporary, lasting a few minutes or hours and normally disappearing completely within 24 hours. There is a 20% risk of major stroke in the first 4 weeks following a TIA and TIA should be treated as an emergency as treatment can minimise risk of further stroke by 80%.