There are two main types of stroke.
Ischaemic strokes happen when something blocks an artery that carries blood to the brain. There are several possible causes:
- a blood clot forms in a main artery to the brain
- a blood clot, air bubble or fat globule forms in a blood vessel and is carried to the brain
- there is a blockage in the tiny bloody vessels deep inside the brain.
Haemorrhagic strokes happen when
a blood vessel bursts and bleeds into
the brain (a haemorrhage).
The haemorrhage may be due to:
- a vessel bursting within the brain itself, or
a blood vessel on the surface of the brain bleeding into the area between the brain and the skull.
Temporary symptoms may indicate a mini-stroke
Sometimes the blockage in the blood supply to the brain is temporary, and a person will have the symptoms of a stroke for a short time. This is called a transient ischaemic attack (TIA) or mini stroke. A TIA is a sign that part of the brain is not getting enough blood, and there is a risk of a more serious stroke in future. As with major strokes, you must seek medical attention immediately.