A stroke is a brain attack. It happens when the blood supply to part of your brain is cut off. Blood carries essential nutrients and oxygen to your brain. Without blood your brain cells can be damaged or die.
Most strokes are caused by a blockage cutting off the blood supply to the brain. This is called an ischaemic stroke.
The blockage can be caused by a blood clot forming in an artery leading to the brain or it can be caused by a blood clot or other matter (such as an air bubble or piece of fatty debris) moving through the blood stream from another part of the body.
Some strokes are caused by bleeding in or around the brain. These are haemorrhagic strokes.
Although they are not as common as ischaemic strokes, this kind of stroke can be much more serious.
A TIA or transient ischaemic attack (also known as a mini-stroke) is the same as a stroke, except that the symptoms last for a short amount of time and no longer than 24 hours.
Although the symptoms may not last long, a TIA is still very serious. It is a sign that there is a problem and you are at risk of having a stroke.
Because of this, a TIA is often called a warning stroke.
A stroke can have different effects, depending on where it happens in your brain.
It can affect the way your body works as well as how you think, feel and communicate.
Stroke occurs approximately 152,000 times a year in the UK and is the fourth single largest cause of death.
It is also the largest cause of complex disability in the UK. Of the 1.3 million stroke survivors that live in the UK, half have a disability.