Stroke - Causes 

Causes of stroke 

Stroke

Someone has a stroke every five minutes in the UK, and strokes are the third most common cause of death. The cause varies from person to person but it's important to know what your personal risk factors are.

Media last reviewed: 14/11/2013

Next review due: 14/11/2015

Could you have high blood pressure?

At least 25% of adults have high blood pressure. Get tips on how to keep healthy

There are two main types of stroke – ischaemic strokes and haemorrhagic strokes – which affect the brain in different ways and can have different causes. 

Ischaemic strokes

Ischaemic strokes are the most common type of stroke. They occur when a blood clot blocks the flow of blood and oxygen to the brain.

These blood clots typically form in areas where the arteries have been narrowed or blocked over time by fatty deposits known as plaques. This process is known as atherosclerosis.

As you get older, the arteries can naturally narrow, but certain things can dangerously accelerate the process. These include:

Another possible cause of ischaemic stroke is a type of irregular heartbeat called atrial fibrillation, which can cause blood clots in the heart that break up and escape from the heart and become lodged in the blood vessels supplying the brain.

Atrial fibrillation can have a number of different causes, including lung disease, heart valve disease, excessive alcohol intake, coronary heart disease, and an overactive thyroid gland  (hyperthyroidism). Read more about the causes of atrial fibrillation.

Haemorrhagic strokes

Haemorrhagic strokes (also known as cerebral haemorrhages or intracranial haemorrhages) are less common than ischaemic strokes. They occur when a blood vessel within the skull bursts and bleeds into and around the brain.

The main cause of haemorrhagic stroke is high blood pressure, which can weaken the arteries in the brain and make them prone to split or rupture.

Things that increase the risk of high blood pressure include:

  • being overweight or obese
  • drinking excessive amounts of alcohol 
  • smoking
  • a lack of exercise 
  • stress, which may cause a temporary rise in blood pressure

Haemorrhagic strokes can also occur as the result of the rupture of a balloon-like expansion of a blood vessel (brain aneurysm) and badly-formed blood vessels in the brain.

Can I reduce my risk?

It's not possible to completely prevent strokes because some things that increase your risk of the condition cannot be changed, including:

  • age you are more likely to have a stroke if you are over 65 years old, although about a quarter of strokes happen in younger people
  • family history if a close relative (parent, grandparent, brother or sister) has had a stroke, your risk is likely to be higher
  • ethnicity if you are south Asian, African or Caribbean, your risk of stroke is higher, partly because rates of diabetes and high blood pressure are higher in these groups
  • your medical history if you have previously had a stroke, transient ischaemic attack (TIA) or heart attack, your risk of stroke is higher

However, in most cases it is possible to significantly reduce your risk of having a stroke by making lifestyle changes to avoid problems such as atherosclerosis and high blood pressure. This includes things such as having a healthy diet, exercising regularly, stopping smoking if you smoke and cutting down on the amount of alcohol you drink.

As atrial fibrillation can also significantly increase your risk of having a stroke, it is also important to seek medical advice if you think you may have an irregular heartbeat. If you are diagnosed with the condition, you should talk to your doctor about the option of taking anticoagulant medications to lower your stroke risk.

Read more about preventing strokes.




Page last reviewed: 08/09/2014

Next review due: 08/09/2016

Ratings

How helpful is this page?

Average rating

Based on 133 ratings

All ratings

Add your rating

Comments

The 2 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Monkfish said on 17 April 2011

An observation, Could allergen be a contributing if not actual cause of stroke? the most sticky ones e.g. Cat Fel D 1 amongst others. Also isn't curvature of spine in old age causing pressure on vertebral arteries more certainly a cause?

Report this content as offensive or unsuitable

Sherlin said on 05 August 2010

Almost 90 percent of strokes are ischemic strokes. They occur when the arteries to your brain are narrowed or blocked, causing severely reduced blood flow (ischemia). Lack of blood flow deprives your brain cells of oxygen and nutrients, and cells may begin to die within minutes. The most common ischemic strokes are: Thrombotic stroke and embolic stroke. In Thrombotic stroke a blood clot is formed in one of the arteries that supply blood to your brain. Whereas in Embolic stroke, an embolic stroke occurs when a blood clot or other debris forms in a blood vessel away from your brain — commonly in your heart.

Report this content as offensive or unsuitable