What is a stroke? The following NHS Choices clip shows what happens in the brain during a stroke and the types of stroke.
A stroke occurs when the flow of blood to part of the brain is cut off.
A stroke is a medical emergency and urgent treatment is essential.
What causes a stroke?
To function properly, braincells need a constant supply of oxygen and nutrients,
which they get from blood.
When the blood supply to part of the brain is suddenly stopped,
braincells become damaged or die.
This can lead to permanent brain damage or even death.
Different areas in the brain
control the function of different parts of the body,
each receiving its blood supply from four main arteries in the neck
and their smaller branches in the brain.
The level of brain damage caused by a stroke varies greatly
and depends on the blood vessel affected.
A stroke may go unnoticed if only a small blood vessel is affected.
But if a large blood vessel is blocked,
it may lead to long-term disability or death.
There are two types of stroke.
Ischaemic stroke is the most common, most often caused by a blood clot
or a piece of fatty material blocking an artery…
..restricting its blood flow
Haemorrhagic stroke is when the walls of a blood vessel in the brain
become weak and burst,
causing bleeding and brain damage.
Transient Ischaemic Attack, TIA or mini stroke,
is similar to a stroke, but the brain’s blood supply is temporarily blocked
and the effects of the blockage get better within 24 hours.
The clot either breaks up quickly
or the affected area receives blood from nearby blood vessels.
TIAs do not cause permanent brain damage,
but are important because they are often a warning sign for a stroke.
Other risk factors for stroke include:
- Increasing age
- Excess alcohol
- High blood pressure
- Stopping smoking
- Reducing alcohol intake
- Regular excercise
..can all help reduce the risk of getting a stroke.
It is important to seek immediate medical attention if you have a stroke.
The sooner you get help, the better the chance of a good recovery.
NHS choices video Neurology section Stroke animation. 2 minutes 43 seconds.