A stroke happens when not enough blood gets to a part of the brain, damaging brain cells. Find out more about stroke and how it is treated.

What is a stroke?

The brain needs oxygen for brain cells to work. Oxygen is carried in the blood. A stroke is when something reduces the amount of blood getting to the brain, damaging or killing brain cells. The effect of a stroke will depend on which area or areas of the brain are damaged. 

Strokes are also known as “cerebrovascular events” (“CVE”s). In the past the term “cerebrovascular accident” (“CVA”) was used. 

There are three main sorts of stroke: 

Ischaemic stroke: this is when an artery to the brain is blocked by a blood clot. It is the commonest type of stroke.   Transient ischaemic attack (“TIA” or mini-stroke): this is a temporary blockage of the arteries to the brain  Haemorrhagic stroke: this is when there is a bleed around or into the brain, stopping the normal blood flow. It not a common form of stroke.

What causes strokes? 

Ischaemic stroke and TIA 

The commonest causes of ischaemic stroke are: 

	Narrowed arteries: the arteries to the brain can be narrowed by a build up of fatty material. If a patch of this fatty material in an artery becomes damaged or starts to break down, a blood clot can form, blocking the artery.
	Irregular heartbeat: atrial fibrillation is a common abnormality of the rhythm of the heart causing an irregular heart beat. This can cause clots to form within the heart which may then travel up to the brain and cause a stroke.

Haemorrhagic stroke 

Blood can leak out when the arteries are damaged or if the arteries are not normal. The blood can leak into the brain itself or around the surface of the brain.

High blood pressure or narrowing of arteries, or a combination of both, puts a strain on the edges of the arteries and can cause damage over a period of time. 

 

What is my risk of a stroke? 

There are a number of things that can put you at risk of a stroke which can be split into things you can control, and those that you can't.

Risk factors that you cannot change:

	Age: stroke is more common as people get older.
	Family history: strokes can run in families, meaning that if a close relative, such as a parent or grandparent, has had a stroke, then your risk is increased. This is usually due to a combination of several genes and also habits that are common amongst the whole family.
	Ethnicity: strokes are more common in South Asian and Black ethnic groups in the UK.
	Sex: women who use the oral contraceptive pill and women who are pregnant are both at a small increased risk of stroke.
	Sickle cell disease: a rare, inherited condition causing abnormal red blood cells that are less able to carry oxygen, increasing the risk of stroke

Risk factors you can do something about:

	High blood pressure: high blood pressure can often be controlled by making changes to your lifestyle, although many people also need medication. Your healthcare team can advise on your blood pressure goal and treatment.
	High cholesterol: eating a healthy diet, maintaining a healthy weight and doing physical activity can all help reduce the risk of a stroke.
	Living with overweight: living with overweight is strongly linked to strokes but the good news is that losing weight helps reduce many of the risk factors.
	Being physically inactive: increasingly physical activity can reduce the risk of having a stroke.
	Smoking: chemicals from cigarettes cause a build up of fatty material in the walls of the arteries increasing the risk of a stroke. Your healthcare team can support you in giving up smoking.
	Having type 2 diabetes: diabetes damages blood vessels, increasing the risk of strokes. Controlling blood sugars reduces the risk of all forms of cardiovascular disease, including stroke.