What is a stroke
- Suzanne Walsh, Advanced Nurse Practitioner
- 2 minute read
- Last updated: July 2023
A stroke is a medical emergency. It happens when the blood supply to part of your brain is disrupted. This stops your brain from getting the constant supply of oxygen and nutrients it needs to work, so brain cells begin to die. It is vital that you get treatment as soon as possible.
Types of stroke
There are three main types of stroke:
- TIA (Transient Ischaemic Attack)
- Ischaemic stroke
- Haemorrhagic stroke
TIA or Transient Ischaemic Attack
A TIA which stands for Transient Ischaemic Attack is caused by a temporary disruption in blood supply to a part of the brain or eye. TIA's resolves within 24 hours and can be a warning sign of a more serious stroke.
Ischaemic stroke
Ischaemic stroke are the most common type of stroke. They happen when a blood clot blocks the flow of blood and oxygen to the brain.
These blood clots can form in the heart, for example due to irregular rhythms such as atrial fibrillation.
Blood clots can also form in the blood vessels themselves, for example due to damage from fatty deposits known as atherosclerosis.
Blood clots can also block blood vessels to the eye causing visual loss or blood vessels to the spinal cord causing weakness, numbness or loss of bladder or bowel control.
There are many other potential causes of ischaemic stroke that your healthcare provider may be able to tell you more about if relevant in your case.
Haemorrhagic stroke
Haemorrhagic stroke (also known as cerebral haemorrhages or intracranial haemorrhages) are less common than ischaemic stroke.
They happen when a blood vessel inside the skull bursts and bleeds into and/or around the brain.
Haemorrhagic stroke can be caused by damage to the small blood vessels in the brain. This damage is most commonly caused by high blood pressure (also known as hypertension) or cerebral amyloid angiopathy (a disease that weakens the blood vessels as we age, due to abnormal build up of a protein called amyloid).
Haemorrhagic stroke can also be caused by rupture of the larger blood vessels in the brain such as due aneurysms or vascular malformations.
There are many other potential causes of haemorrhagic stroke which your healthcare provider can tell you more about if relevant in your case.
